A recent vulnerability, CVE-2025-0475, has been discovered in GitLab CE/EE (Community Edition and Enterprise Edition) affecting all versions between 15.10 and 17.7.6, as well as 17.8+ releases up to 17.8.4, and 17.9 releases prior to 17.9.1. In certain situations, the proxy feature enabled in GitLab could lead to unintended content rendering, causing a cross-site scripting (XSS) security risk.

Vulnerability Details

Cross-Site Scripting (XSS) is a type of security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users, potentially giving them unauthorized access to sensitive information or user accounts. In this case, GitLab's proxy feature could lead to XSS by rendering unexpected content when specific conditions are met. This is a particularly concerning issue as GitLab is a widely used web-based DevOps management tool.

To give a better understanding of the vulnerability, let's examine some example code that demonstrates the issue:

<!-- Vulnerable code snippet -->
<script>
  function displayUsername(username){
    document.getElementById('username-display').innerHTML = username;
  }
</script>

In the sample code above, the function 'displayUsername' takes a 'username' input and sets it as the innerHTML element of the 'username-display' element without any proper sanitization or validation. This can lead to an attacker injecting malicious payloads that will be executed in the victim's browser.

Here's an example payload that an attacker could use to exploit this vulnerability

<!-- Malicious payload -->
<script>
  // Execute the displayUsername() function with the XSS payload
  displayUsername('<img src=x onerror=alert(1)>');
</script>

With the malicious payload above, instead of displaying the expected username, an alert with the value '1' would be triggered due to the execution of the malicious payload inserted by the attacker.

To further illustrate the severity of this vulnerability, check out these original references that provide more in-depth information on the issue:

1. GitLab Advisory
2. National Vulnerability Database

Mitigation

GitLab has already acknowledged CVE-2025-0475 and released an updated version of GitLab CE/EE to address this vulnerability. The fixed versions include 17.7.6, 17.8.4, and 17.9.1. It is highly recommended that GitLab users upgrade to one of these patched versions to protect themselves from potential exploitation.

If you are unable to immediately update to a patched version, you can mitigate this vulnerability by disabling the proxy feature or implementing strict content security policies (CSP) that would prevent the execution of inline JavaScript code.

Conclusion

CVE-2025-0475 is a significant security concern for GitLab users, and it is crucial to take necessary measures to protect your web applications from potential exploitation by attackers. Make sure to update your GitLab CE/EE to the latest patched version, and always keep your software up-to-date to minimize your exposure to security vulnerabilities like this one. Stay safe!

Timeline

Published on: 03/03/2025 11:15:15 UTC
Last modified on: 03/07/2025 12:30:28 UTC