CVE-2025-0555
📋 TL;DR
This Cross-Site Scripting (XSS) vulnerability in GitLab Enterprise Edition allows attackers to bypass security controls and execute malicious scripts in users' browsers under specific conditions. All GitLab-EE instances running versions 16.6 through 17.7.5, 17.8 through 17.8.3, or 17.9 through 17.9.0 are affected.
💻 Affected Systems
- GitLab Enterprise Edition
📦 What is this software?
Gitlab by Gitlab
GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...
Learn more about Gitlab →Gitlab by Gitlab
GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...
Learn more about Gitlab →Gitlab by Gitlab
GitLab is a complete DevOps platform providing source code management, CI/CD pipelines, security scanning, container registry, and collaboration tools used by millions of developers and thousands of enterprises worldwide. As both a cloud-hosted SaaS offering (GitLab.com) and self-managed software, G...
Learn more about Gitlab →⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, perform actions as authenticated users, redirect to malicious sites, or compromise user accounts and data.
Likely Case
Session hijacking, credential theft, or unauthorized actions performed in the context of logged-in users.
If Mitigated
Limited impact with proper Content Security Policy (CSP) headers, input validation, and output encoding in place.
🎯 Exploit Status
Exploitation requires specific conditions and likely some level of user interaction or authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 17.7.6, 17.8.4, or 17.9.1
Vendor Advisory: https://gitlab.com/gitlab-org/gitlab/-/issues/514004
Restart Required: Yes
Instructions:
1. Backup your GitLab instance. 2. Update to GitLab-EE 17.7.6, 17.8.4, or 17.9.1 using your preferred method (Omnibus package, Docker, source). 3. Restart GitLab services. 4. Verify the update was successful.
🔧 Temporary Workarounds
Implement Content Security Policy
allAdd CSP headers to restrict script execution sources
Add to nginx config: add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval';" always;
Input Validation Filter
allImplement additional input validation for user-controlled data
Configure GitLab application settings to enforce strict input validation
🧯 If You Can't Patch
- Implement strict Content Security Policy headers
- Enable additional XSS protection mechanisms in web application firewall
🔍 How to Verify
Check if Vulnerable:
Check GitLab version via admin interface or command: sudo gitlab-rake gitlab:env:info | grep 'GitLab version'Check Version:
sudo gitlab-rake gitlab:env:info | grep 'GitLab version'Verify Fix Applied:
Confirm version is 17.7.6, 17.8.4, 17.9.1 or higher📡 Detection & Monitoring
Log Indicators:
- Unusual JavaScript payloads in request logs
- Suspicious script tags in user input fields
Network Indicators:
- Unexpected external script loads from GitLab pages
- Suspicious redirect patterns
SIEM Query:
source="gitlab_access.log" AND ("<script>" OR "javascript:" OR "onerror=" OR "onload=")