CVE-2025-1516: GitLab Token Names DoS Vulnerability

CVE-2025-1516 Overview

A denial of service vulnerability has been discovered in GitLab CE/EE affecting all versions from 8.7. The vulnerability stems from improper input validation in Token Names functionality, which can be exploited by attackers to trigger resource exhaustion and cause a denial of service condition. This vulnerability allows unauthenticated attackers to disrupt GitLab service availability through specially crafted token name inputs.

Critical Impact

Attackers can exploit improper input validation in GitLab Token Names to cause denial of service, potentially disrupting CI/CD pipelines, code repositories, and collaborative development workflows across affected organizations.

Affected Products

• GitLab Community Edition (CE) versions 8.7 to before 17.10.8
• GitLab Enterprise Edition (EE) versions 17.11 to before 17.11.4
• GitLab CE/EE versions 18.0 to before 18.0.2

Discovery Timeline

• 2025-06-12 - CVE CVE-2025-1516 published to NVD
• 2025-08-08 - Last updated in NVD database

Technical Details for CVE-2025-1516

Vulnerability Analysis

This vulnerability is classified under CWE-770 (Allocation of Resources Without Limits or Throttling). The flaw exists in the token names handling mechanism within GitLab, where insufficient input validation allows attackers to provide malicious input that triggers excessive resource allocation. The vulnerability is network-accessible without requiring authentication or user interaction, making it particularly concerning for publicly accessible GitLab instances.

The improper input validation flaw can lead to resource exhaustion when processing specially crafted token names, ultimately resulting in service unavailability. Given that GitLab serves as a critical component in modern DevOps workflows, exploitation of this vulnerability could significantly impact software development operations.

Root Cause

The root cause of this vulnerability lies in the inadequate validation and sanitization of token name inputs within GitLab's token management functionality. When processing token names, the application fails to properly limit or throttle resource allocation, allowing attackers to craft inputs that consume excessive system resources. This design flaw enables denial of service attacks by exhausting server-side resources through repeated or specially formatted requests.

Attack Vector

The attack vector for CVE-2025-1516 is network-based, requiring no privileges or user interaction. An attacker can remotely exploit this vulnerability by sending specially crafted requests containing malicious token names to a vulnerable GitLab instance. The attack does not require authentication, allowing any network-accessible attacker to target vulnerable systems.

The exploitation process involves submitting token name inputs designed to trigger resource exhaustion in the GitLab application. This could involve extremely long strings, special characters, or patterns that cause excessive processing or memory allocation in the token handling logic.

Detection Methods for CVE-2025-1516

Indicators of Compromise

• Unusual spikes in memory consumption or CPU utilization on GitLab servers
• Excessive requests to token-related API endpoints from single or multiple sources
• GitLab application logs showing errors related to token processing or resource limits
• Service degradation or unresponsiveness of GitLab web interface and API

Detection Strategies

• Monitor GitLab application logs for unusual patterns in token creation or modification requests
• Implement rate limiting detection on API endpoints related to token management
• Configure alerts for abnormal resource consumption patterns on GitLab servers
• Review web application firewall (WAF) logs for suspicious payloads targeting token endpoints

Monitoring Recommendations

• Enable detailed logging for GitLab token-related operations and API calls
• Configure infrastructure monitoring to alert on memory and CPU threshold breaches
• Implement network traffic analysis to identify potential DoS attack patterns
• Set up automated alerts for GitLab service availability degradation

How to Mitigate CVE-2025-1516

Immediate Actions Required

• Upgrade GitLab CE/EE to patched versions: 17.10.8, 17.11.4, or 18.0.2 or later
• Implement rate limiting on token-related API endpoints as a temporary measure
• Review and restrict network access to GitLab instances where possible
• Monitor systems for signs of active exploitation attempts

Patch Information

GitLab has released security patches addressing this vulnerability. Organizations should upgrade to the following patched versions:

• Version 17.10.8 for the 17.10.x branch
• Version 17.11.4 for the 17.11.x branch
• Version 18.0.2 for the 18.0.x branch

For detailed information about the vulnerability and patch, refer to the GitLab Issue Discussion and HackerOne Report #2991435.

Workarounds

• Implement web application firewall (WAF) rules to filter malicious token name inputs
• Configure rate limiting at the load balancer or reverse proxy level for token endpoints
• Restrict network access to GitLab instances to trusted IP ranges where feasible
• Enable resource limits and quotas on the GitLab application server

# Example: Configure nginx rate limiting for GitLab token endpoints
# Add to nginx configuration
limit_req_zone $binary_remote_addr zone=token_limit:10m rate=10r/s;

location ~ ^/api/v4/.*/tokens {
    limit_req zone=token_limit burst=20 nodelay;
    proxy_pass http://gitlab-workhorse;
}