hacktricks/pentesting-web/reverse-tab-nabbing.md



{% hint style="success" %}
Learn & practice AWS Hacking:<img src="/.gitbook/assets/arte.png" alt="" data-size="line">[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)<img src="/.gitbook/assets/arte.png" alt="" data-size="line">\
Learn & practice GCP Hacking: <img src="/.gitbook/assets/grte.png" alt="" data-size="line">[**HackTricks Training GCP Red Team Expert (GRTE)**<img src="/.gitbook/assets/grte.png" alt="" data-size="line">](https://training.hacktricks.xyz/courses/grte)

<details>

<summary>Support HackTricks</summary>

* Check the [**subscription plans**](https://github.com/sponsors/carlospolop)!
* **Join the** 💬 [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** us on **Twitter** 🐦 [**@hacktricks\_live**](https://twitter.com/hacktricks\_live)**.**
* **Share hacking tricks by submitting PRs to the** [**HackTricks**](https://github.com/carlospolop/hacktricks) and [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.

</details>
{% endhint %}


# Description

In a situation where an **attacker** can **control** the **`href`** argument of an **`<a`** tag with the attribute **`target="_blank" rel="opener"`** that is going to be clicked by a victim, the **attacker** **point** this **link** to a web under his control (a **malicious** **website**). Then, once the **victim clicks** the link and access the attackers website, this **malicious** **website** will be able to **control** the **original** **page** via the javascript object **`window.opener`**.\
If the page doesn't have **`rel="opener"` but contains `target="_blank"` it also doesn't have `rel="noopener"`** it might be also vulnerable.

A regular way to abuse this behaviour would be to **change the location of the original web** via `window.opener.location = https://attacker.com/victim.html` to a web controlled by the attacker that **looks like the original one**, so it can **imitate** the **login** **form** of the original website and ask for credentials to the user.

However, note that as the **attacker now can control the window object of the original website** he can abuse it in other ways to perform **stealthier attacks** (maybe modifying javascript events to ex-filtrate info to a server controlled by him?)

# Overview

## With back link

Link between parent and child pages when prevention attribute is not used:

![https://owasp.org/www-community/assets/images/TABNABBING_OVERVIEW_WITH_LINK.png](https://owasp.org/www-community/assets/images/TABNABBING\_OVERVIEW\_WITH\_LINK.png)

## Without back link

Link between parent and child pages when prevention attribute is used:

![https://owasp.org/www-community/assets/images/TABNABBING_OVERVIEW_WITHOUT_LINK.png](https://owasp.org/www-community/assets/images/TABNABBING\_OVERVIEW\_WITHOUT\_LINK.png)

## Examples <a href="#examples" id="examples"></a>

Create the following pages in a folder and run a web server with `python3 -m http.server`\
Then, **access** `http://127.0.0.1:8000/`vulnerable.html, **click** on the link and note how the **original** **website** **URL** **changes**.

{% code title="vulnerable.html" %}
```markup
<!DOCTYPE html>
<html>
<body>
<h1>Victim Site</h1>
<a href="http://127.0.0.1:8000/malicious.html" target="_blank" rel="opener">Controlled by the attacker</a>
</body>
</html>
```
{% endcode %}

{% code title="malicious.html" %}
```markup
<!DOCTYPE html>
<html>
 <body>
  <script>
  window.opener.location = "http://127.0.0.1:8000/malicious_redir.html";
  </script>
 </body>
</html>
```
{% endcode %}

{% code title="malicious_redir.html" %}
```markup
<!DOCTYPE html>
<html>
<body>
<h1>New Malicious Site</h1>
</body>
</html>
```
{% endcode %}

## Accessible properties <a href="#accessible-properties" id="accessible-properties"></a>

In the scenario where a **cross-origin** access occurs (access across different domains), the properties of the **window** JavaScript class instance, referred to by the **opener** JavaScript object reference, that can be accessed by a malicious site are limited to the following:

- **`opener.closed`**: This property is accessed to determine if a window has been closed, returning a boolean value.
- **`opener.frames`**: This property provides access to all iframe elements within the current window.
- **`opener.length`**: The number of iframe elements present in the current window is returned by this property.
- **`opener.opener`**: A reference to the window that opened the current window can be obtained through this property.
- **`opener.parent`**: This property returns the parent window of the current window.
- **`opener.self`**: Access to the current window itself is provided by this property.
- **`opener.top`**: This property returns the topmost browser window.

However, in instances where the domains are identical, the malicious site gains access to all properties exposed by the [**window**](https://developer.mozilla.org/en-US/docs/Web/API/Window) JavaScript object reference.

# Prevention

Prevention information are documented into the [HTML5 Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/HTML5\_Security\_Cheat\_Sheet.html#tabnabbing).

## References

* [https://owasp.org/www-community/attacks/Reverse_Tabnabbing](https://owasp.org/www-community/attacks/Reverse_Tabnabbing)


{% hint style="success" %}
Learn & practice AWS Hacking:<img src="/.gitbook/assets/arte.png" alt="" data-size="line">[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)<img src="/.gitbook/assets/arte.png" alt="" data-size="line">\
Learn & practice GCP Hacking: <img src="/.gitbook/assets/grte.png" alt="" data-size="line">[**HackTricks Training GCP Red Team Expert (GRTE)**<img src="/.gitbook/assets/grte.png" alt="" data-size="line">](https://training.hacktricks.xyz/courses/grte)

<details>

<summary>Support HackTricks</summary>

* Check the [**subscription plans**](https://github.com/sponsors/carlospolop)!
* **Join the** 💬 [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** us on **Twitter** 🐦 [**@hacktricks\_live**](https://twitter.com/hacktricks\_live)**.**
* **Share hacking tricks by submitting PRs to the** [**HackTricks**](https://github.com/carlospolop/hacktricks) and [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud) github repos.

</details>
{% endhint %}
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00

b 2024-07-19 09:06:54 +00:00			`{% hint style="success" %}`
			`Learn & practice AWS Hacking:<img src="/.gitbook/assets/arte.png" alt="" data-size="line">[HackTricks Training AWS Red Team Expert (ARTE)](https://training.hacktricks.xyz/courses/arte)<img src="/.gitbook/assets/arte.png" alt="" data-size="line">\`
			`Learn & practice GCP Hacking: <img src="/.gitbook/assets/grte.png" alt="" data-size="line">[HackTricks Training GCP Red Team Expert (GRTE)<img src="/.gitbook/assets/grte.png" alt="" data-size="line">](https://training.hacktricks.xyz/courses/grte)`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00
b 2024-07-19 09:06:54 +00:00			`<details>`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00
b 2024-07-19 09:06:54 +00:00			`<summary>Support HackTricks</summary>`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00
b 2024-07-19 09:06:54 +00:00			`* Check the [subscription plans](https://github.com/sponsors/carlospolop)!`
			`* Join the 💬 [Discord group](https://discord.gg/hRep4RUj7f) or the [telegram group](https://t.me/peass) or follow us on Twitter 🐦 [@hacktricks\_live](https://twitter.com/hacktricks\_live).`
			`* Share hacking tricks by submitting PRs to the [HackTricks](https://github.com/carlospolop/hacktricks) and [HackTricks Cloud](https://github.com/carlospolop/hacktricks-cloud) github repos.`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00
			`</details>`
b 2024-07-19 09:06:54 +00:00			`{% endhint %}`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00

fix mess 2022-05-01 12:41:36 +00:00			`# Description`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
GitBook: [#2777] gitbookissooooo slow I cannot write 2021-10-18 11:21:18 +00:00			In a situation where an attacker can control the `href` argument of an `<a` tag with the attribute `target="_blank" rel="opener"` that is going to be clicked by a victim, the attacker point this link to a web under his control (a malicious website). Then, once the victim clicks the link and access the attackers website, this malicious website will be able to control the original page via the javascript object `window.opener`.\
GitBook: [master] one page modified 2021-08-28 15:55:37 +00:00			If the page doesn't have `rel="opener"` but contains `target="_blank"` it also doesn't have `rel="noopener"` it might be also vulnerable.
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
GitBook: [master] one page modified 2021-08-28 15:55:37 +00:00			A regular way to abuse this behaviour would be to change the location of the original web via `window.opener.location = https://attacker.com/victim.html` to a web controlled by the attacker that looks like the original one, so it can imitate the login form of the original website and ask for credentials to the user.
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
GitBook: [#2876] save 2021-11-30 16:46:07 +00:00			`However, note that as the attacker now can control the window object of the original website he can abuse it in other ways to perform stealthier attacks (maybe modifying javascript events to ex-filtrate info to a server controlled by him?)`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
fix mess 2022-05-01 12:41:36 +00:00			`# Overview`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
fix mess 2022-05-01 12:41:36 +00:00			`## With back link`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
			`Link between parent and child pages when prevention attribute is not used:`

a 2024-02-06 03:10:38 +00:00			`![https://owasp.org/www-community/assets/images/TABNABBING_OVERVIEW_WITH_LINK.png](https://owasp.org/www-community/assets/images/TABNABBING\_OVERVIEW\_WITH\_LINK.png)`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
fix mess 2022-05-01 12:41:36 +00:00			`## Without back link`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
			`Link between parent and child pages when prevention attribute is used:`

a 2024-02-06 03:10:38 +00:00			`![https://owasp.org/www-community/assets/images/TABNABBING_OVERVIEW_WITHOUT_LINK.png](https://owasp.org/www-community/assets/images/TABNABBING\_OVERVIEW\_WITHOUT\_LINK.png)`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
fix mess 2022-05-01 12:41:36 +00:00			`## Examples <a href="#examples" id="examples"></a>`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
GitBook: [#2777] gitbookissooooo slow I cannot write 2021-10-18 11:21:18 +00:00			Create the following pages in a folder and run a web server with `python3 -m http.server`\
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00			Then, access `http://127.0.0.1:8000/`vulnerable.html, click on the link and note how the original website URL changes.

			`{% code title="vulnerable.html" %}`
			```markup
			`<!DOCTYPE html>`
			`<html>`
			`<body>`
			`<h1>Victim Site</h1>`
			`<a href="http://127.0.0.1:8000/malicious.html" target="_blank" rel="opener">Controlled by the attacker</a>`
			`</body>`
			`</html>`
			```
			`{% endcode %}`

			`{% code title="malicious.html" %}`
			```markup
			`<!DOCTYPE html>`
			`<html>`
			`<body>`
			`<script>`
			`window.opener.location = "http://127.0.0.1:8000/malicious_redir.html";`
			`</script>`
			`</body>`
			`</html>`
			```
			`{% endcode %}`

GitBook: [#2777] gitbookissooooo slow I cannot write 2021-10-18 11:21:18 +00:00			`{% code title="malicious_redir.html" %}`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00			```markup
			`<!DOCTYPE html>`
			`<html>`
			`<body>`
			`<h1>New Malicious Site</h1>`
			`</body>`
			`</html>`
			```
			`{% endcode %}`

fix mess 2022-05-01 12:41:36 +00:00			`## Accessible properties <a href="#accessible-properties" id="accessible-properties"></a>`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
a 2024-02-06 03:10:38 +00:00			`In the scenario where a cross-origin access occurs (access across different domains), the properties of the window JavaScript class instance, referred to by the opener JavaScript object reference, that can be accessed by a malicious site are limited to the following:`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
a 2024-02-06 03:10:38 +00:00			- `opener.closed`: This property is accessed to determine if a window has been closed, returning a boolean value.
			- `opener.frames`: This property provides access to all iframe elements within the current window.
			- `opener.length`: The number of iframe elements present in the current window is returned by this property.
			- `opener.opener`: A reference to the window that opened the current window can be obtained through this property.
			- `opener.parent`: This property returns the parent window of the current window.
			- `opener.self`: Access to the current window itself is provided by this property.
			- `opener.top`: This property returns the topmost browser window.
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
a 2024-02-06 03:10:38 +00:00			`However, in instances where the domains are identical, the malicious site gains access to all properties exposed by the [window](https://developer.mozilla.org/en-US/docs/Web/API/Window) JavaScript object reference.`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
fix mess 2022-05-01 12:41:36 +00:00			`# Prevention`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
GitBook: [#2876] save 2021-11-30 16:46:07 +00:00			`Prevention information are documented into the [HTML5 Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/HTML5\_Security\_Cheat\_Sheet.html#tabnabbing).`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
a 2024-02-08 03:08:28 +00:00			`## References`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
a 2024-02-06 03:10:38 +00:00			`* [https://owasp.org/www-community/attacks/Reverse_Tabnabbing](https://owasp.org/www-community/attacks/Reverse_Tabnabbing)`
GitBook: [master] 456 pages modified 2021-05-01 15:23:19 +00:00
fix bad chars 2022-04-05 22:24:52 +00:00
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00

b 2024-07-19 09:06:54 +00:00			`{% hint style="success" %}`
			`Learn & practice AWS Hacking:<img src="/.gitbook/assets/arte.png" alt="" data-size="line">[HackTricks Training AWS Red Team Expert (ARTE)](https://training.hacktricks.xyz/courses/arte)<img src="/.gitbook/assets/arte.png" alt="" data-size="line">\`
			`Learn & practice GCP Hacking: <img src="/.gitbook/assets/grte.png" alt="" data-size="line">[HackTricks Training GCP Red Team Expert (GRTE)<img src="/.gitbook/assets/grte.png" alt="" data-size="line">](https://training.hacktricks.xyz/courses/grte)`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00
b 2024-07-19 09:06:54 +00:00			`<details>`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00
b 2024-07-19 09:06:54 +00:00			`<summary>Support HackTricks</summary>`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00
b 2024-07-19 09:06:54 +00:00			`* Check the [subscription plans](https://github.com/sponsors/carlospolop)!`
			`* Join the 💬 [Discord group](https://discord.gg/hRep4RUj7f) or the [telegram group](https://t.me/peass) or follow us on Twitter 🐦 [@hacktricks\_live](https://twitter.com/hacktricks\_live).`
			`* Share hacking tricks by submitting PRs to the [HackTricks](https://github.com/carlospolop/hacktricks) and [HackTricks Cloud](https://github.com/carlospolop/hacktricks-cloud) github repos.`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00
			`</details>`
b 2024-07-19 09:06:54 +00:00			`{% endhint %}`
Ad hacktricks sponsoring 2022-04-28 16:01:33 +00:00