CVE-2025-4225
📋 TL;DR
This vulnerability allows unauthenticated attackers to send specially crafted GraphQL requests to GitLab instances, causing denial-of-service conditions that affect all users. It affects GitLab Community Edition and Enterprise Edition installations running vulnerable versions. The attack requires no authentication and can be performed remotely.
💻 Affected Systems
- GitLab Community Edition
- 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 →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
Complete service unavailability for all GitLab users, potentially disrupting development workflows, CI/CD pipelines, and code collaboration across the organization.
Likely Case
Temporary service degradation or outages affecting GitLab web interface, API access, and integrated services until the attack stops or the system recovers.
If Mitigated
Minimal impact with proper rate limiting, WAF rules, and network segmentation preventing the crafted requests from reaching vulnerable endpoints.
🎯 Exploit Status
The vulnerability is in GraphQL handling, which is typically exposed. No authentication required makes exploitation straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 18.1.5, 18.2.5, 18.3.1 or later
Vendor Advisory: https://gitlab.com/gitlab-org/gitlab/-/issues/538983
Restart Required: Yes
Instructions:
1. Backup your GitLab instance. 2. Update to GitLab 18.1.5, 18.2.5, or 18.3.1 depending on your current version track. 3. Restart GitLab services. 4. Verify the update completed successfully.
🔧 Temporary Workarounds
Rate Limit GraphQL Endpoints
linuxImplement rate limiting on /api/graphql endpoints to prevent DoS attacks
# Configure in GitLab nginx config or external WAF
# Example: limit_req_zone $binary_remote_addr zone=graphql:10m rate=10r/s;
# Then apply to GraphQL location block
WAF Rule for GraphQL Requests
allDeploy Web Application Firewall rules to block suspicious GraphQL queries
# ModSecurity or cloud WAF example rule
# Detect excessive GraphQL queries from single IP
SecRule REQUEST_URI "@streq /api/graphql" \
"id:1001,phase:1,block,msg:'Potential GraphQL DoS attempt'"
🧯 If You Can't Patch
- Implement strict network access controls to limit GraphQL endpoint exposure to trusted IPs only
- Deploy a reverse proxy with request inspection and filtering for GraphQL queries
🔍 How to Verify
Check if Vulnerable:
Check GitLab version with: sudo gitlab-rake gitlab:env:info | grep 'Version:'Check Version:
sudo gitlab-rake gitlab:env:info | grep 'Version:'Verify Fix Applied:
Confirm version is 18.1.5+, 18.2.5+, or 18.3.1+ and test GraphQL endpoint functionality📡 Detection & Monitoring
Log Indicators:
- High volume of GraphQL requests from single IPs
- Increased error rates in GraphQL endpoints
- Unusual query patterns in /var/log/gitlab/gitlab-rails/production.log
Network Indicators:
- Spike in traffic to /api/graphql endpoint
- Multiple malformed GraphQL queries from same source
SIEM Query:
source="gitlab" AND (uri_path="/api/graphql") AND (status>=500 OR request_count>1000) | stats count by src_ip