A newly discovered vulnerability (CVE-2024-8179) in GitLab Community Edition (CE) and Enterprise Edition (EE) has been recently identified. This security issue affects all GitLab versions starting from 17.3 and before the following specific patched versions: 17.4.6, 17.5.4, and 17.6.2. The vulnerability is caused due to improper output encoding, which may result in Cross-Site Scripting (XSS) attacks if the Content Security Policy (CSP) is not enabled. In this blog post, we will describe the vulnerability, provide code snippets, link to original references, and offer exploitation details.

Vulnerability (CVE-2024-8179) Details

GitLab CE/EE does not properly encode the output in certain scenarios, allowing a malicious user to inject arbitrary HTML and script code into the web application. If a site's Content Security Policy (CSP) is misconfigured or disabled, this can lead to a successful XSS attack.

A successful XSS attack can result in various security risks, such as stealing user credentials, redirecting users to malicious websites, and performing unauthorized actions on behalf of users.

The following code snippet demonstrates an unpatched area with improper output encoding in GitLab

function displayOutput() {
  var input = document.getElementById('userInput').value;
  var output = document.getElementById('output');
  output.innerHTML = "Hello, " + input + "!";
}

In the code snippet above, the user input is directly appended to the output without proper output encoding. This means that a malicious user could insert a script tag with a payload to potentially exploit this vulnerability.

For instance, an attacker could submit the following input as their username

<script>alert('XSS Payload');</script>

If the CSP is not enabled or misconfigured, this input will be executed in the victim's browser as shown in the example below:

function displayOutput() {
  var input = "<script>alert('XSS Payload');</script>";
  var output = document.getElementById('output');
  output.innerHTML = "Hello, " + input + "!";
}

The script injected by the attacker will be executed, successfully exploiting the XSS vulnerability.

Mitigation and Solution

To resolve this issue, GitLab encourages users to upgrade their GitLab CE/EE installations to the latest, patched versions: 17.4.6, 17.5.4, and 17.6.2. Moreover, it is vital to ensure that the Content Security Policy (CSP) is properly configured and enabled on the affected websites.

1. GitLab Security Advisory: https://about.gitlab.com/releases/2022/04/22/security-release-gitlab-17-4-6-released/
2. CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-8179
3. National Vulnerability Database (NVD): https://nvd.nist.gov/vuln/detail/CVE-2024-8179

Conclusion

The recent discovery of the security issue (CVE-2024-8179) in GitLab CE/EE highlights the importance of keeping your software up to date and properly configuring the Content Security Policy (CSP) on your websites. By upgrading GitLab to the latest, patched versions and ensuring your CSP is enabled, you can protect your users and applications from potential XSS attacks. Stay safe and vigilant in the ever-evolving digital landscape!

Timeline

Published on: 12/12/2024 12:15:27 UTC