hacktricks/pentesting-web/dependency-confusion.md

# Dependency Confusion

<details>

<summary><strong>Learn AWS hacking from zero to hero with</strong> <a href="https://training.hacktricks.xyz/courses/arte"><strong>htARTE (HackTricks AWS Red Team Expert)</strong></a><strong>!</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** 🐦[**@carlospolopm**](https://twitter.com/hacktricks_live)**.**
* **Share your hacking tricks by submitting PRs to the [hacktricks repo](https://github.com/carlospolop/hacktricks) and [hacktricks-cloud repo](https://github.com/carlospolop/hacktricks-cloud)**.

</details>

<figure><img src="https://pentest.eu/RENDER_WebSec_10fps_21sec_9MB_29042024.gif" alt=""><figcaption></figcaption></figure>

{% embed url="https://websec.nl/" %}


## Basic Information

In summary, a dependency confusion vulnerability occurs when a project is using a library with a **misspelled** name, **inexistent** or with an **unspecified version** and the used dependency repository allows to **gather updated versions from public** repositories.

* **Misspelled**: Import **`reqests`** instead of `requests`
* **Inexistent**: Import `company-logging`, an internal library which **no longer exists**
* **Unspecified version**: Import an **internal** **existent** `company-requests` library , but the repo check **public repos** to see if there are **greater versions**.

## Exploitation

{% hint style="warning" %}
In all cases the attacker just need to publish a **malicious package with name** of libraries used by the victim company.
{% endhint %}

### Misspelled & Inexistent

If your company is trying to **import a library that isn't internal**, highly probably the repo of libraries is going to be searching for it in **public repositories**. If an attacker has created it, your code and machines running is highly probably going to be compromised.

### Unspecified Version

It's very common for developers to **not specify any version** of the library used, or specify just a **mayor version**. Then, the interpreter will try to download the **latest version** fitting those requirements.\
If the library is a **known external library** (like python `requests`), an **attacker cannot do much**, as he won't be able to create a library called `requests` (unless he is the original author).\
However, if the library is **internal**, like `requests-company` in this example, if the **library repo** allows to **check for new versions also externally**, it will search for a newer version publicly available.\
So if an **attacker knows** that the company is using the `requests-company` library **version 1.0.1** (allow minor updates). He can **publish** the library `requests-company` **version 1.0.2** and the company will **use that library instead** of the internal one.

## AWS Fix

This vulnerability was found in AWS **CodeArtifact** (read the [**details in this blog post**](https://zego.engineering/dependency-confusion-in-aws-codeartifact-86b9ff68963d)).\
AWS fixed this by allowing to specify if a library is internal or external, to avoid downloading internal dependencied from external repositories.

## Finding Vulnerable Libraries

In the [**original post about dependency confusion**](https://medium.com/@alex.birsan/dependency-confusion-4a5d60fec610) the author searched for thousands of exposed package.json files containing javascript project’s dependencies.

## References

* [https://medium.com/@alex.birsan/dependency-confusion-4a5d60fec610](https://medium.com/@alex.birsan/dependency-confusion-4a5d60fec610)
* [https://zego.engineering/dependency-confusion-in-aws-codeartifact-86b9ff68963d](https://zego.engineering/dependency-confusion-in-aws-codeartifact-86b9ff68963d)

<figure><img src="https://pentest.eu/RENDER_WebSec_10fps_21sec_9MB_29042024.gif" alt=""><figcaption></figcaption></figure>

{% embed url="https://websec.nl/" %}

<details>

<summary><strong>Learn AWS hacking from zero to hero with</strong> <a href="https://training.hacktricks.xyz/courses/arte"><strong>htARTE (HackTricks AWS Red Team Expert)</strong></a><strong>!</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** 🐦[**@carlospolopm**](https://twitter.com/hacktricks_live)**.**
* **Share your hacking tricks by submitting PRs to the [hacktricks repo](https://github.com/carlospolop/hacktricks) and [hacktricks-cloud repo](https://github.com/carlospolop/hacktricks-cloud)**.

</details>