CVE-2025-0993: GitLab CE/EE Denial of Service Vulnerability

CVE-2025-0993 Overview

A denial of service vulnerability has been discovered in GitLab CE/EE that allows an authenticated attacker to exhaust server resources, potentially causing service disruption. This vulnerability affects all versions before 17.10.7, versions 17.11 before 17.11.3, and version 18.0 before 18.0.1. The flaw is classified as CWE-770 (Allocation of Resources Without Limits or Throttling), indicating improper resource management within the application.

Critical Impact

Authenticated attackers can leverage this vulnerability to cause denial of service conditions by exhausting server resources, potentially disrupting GitLab services for all users in affected environments.

Affected Products

• GitLab Community Edition (CE) all versions before 17.10.7
• GitLab Enterprise Edition (EE) all versions before 17.10.7
• GitLab CE/EE versions 17.11 before 17.11.3
• GitLab CE/EE version 18.0.0

Discovery Timeline

• 2025-05-22 - CVE-2025-0993 published to NVD
• 2025-05-29 - Last updated in NVD database

Technical Details for CVE-2025-0993

Vulnerability Analysis

This vulnerability stems from improper resource allocation controls within GitLab CE/EE. The flaw allows authenticated users to trigger resource-intensive operations without adequate throttling or limits, leading to server resource exhaustion. The attack can be executed remotely over the network and requires low privileges (authenticated user access), making it accessible to any user with valid GitLab credentials.

The impact is limited to availability—there is no compromise of confidentiality or integrity. However, successful exploitation can render GitLab services unavailable to legitimate users, disrupting development workflows and CI/CD pipelines.

Root Cause

The root cause is CWE-770: Allocation of Resources Without Limits or Throttling. GitLab fails to properly constrain resource allocation for certain operations, allowing authenticated users to consume excessive server resources such as memory, CPU, or storage through repeated or specially crafted requests.

Attack Vector

The attack vector is network-based, requiring only authenticated access with low privileges. An attacker with a valid GitLab account can exploit this vulnerability without any user interaction. The attack targets the availability of the GitLab server by exhausting system resources.

The vulnerability mechanism involves resource exhaustion through uncontrolled allocation. Authenticated users can initiate operations that consume server resources without proper rate limiting or resource caps. For detailed technical information, refer to the GitLab Issue Report and HackerOne Security Report #2967771.

Detection Methods for CVE-2025-0993

Indicators of Compromise

• Unusual spikes in server resource utilization (CPU, memory, disk I/O) correlated with GitLab operations
• Abnormal request patterns from authenticated users targeting resource-intensive endpoints
• Repeated timeouts or service degradation reports from GitLab users
• Log entries indicating resource limit warnings or out-of-memory conditions

Detection Strategies

• Monitor GitLab application logs for repeated requests from single users that correlate with resource spikes
• Implement rate limiting detection at the web application firewall (WAF) level for GitLab endpoints
• Configure alerting for abnormal resource consumption patterns on GitLab servers
• Enable audit logging to track user activities that may indicate exploitation attempts

Monitoring Recommendations

• Set up infrastructure monitoring with alerts for CPU and memory thresholds on GitLab servers
• Deploy application performance monitoring (APM) to identify resource-intensive request patterns
• Configure centralized logging to correlate user activities with system resource metrics
• Establish baseline resource utilization patterns to detect anomalous behavior

How to Mitigate CVE-2025-0993

Immediate Actions Required

• Upgrade GitLab CE/EE to version 17.10.7 or later for the 17.10.x branch
• Upgrade GitLab CE/EE to version 17.11.3 or later for the 17.11.x branch
• Upgrade GitLab CE/EE to version 18.0.1 or later for the 18.0.x branch
• Review and restrict user access to minimize the pool of potential attackers

Patch Information

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

• Version 17.10.7 or later (for 17.10.x installations)
• Version 17.11.3 or later (for 17.11.x installations)
• Version 18.0.1 or later (for 18.0.x installations)

For additional details, consult the GitLab Issue Report.

Workarounds

• Implement network-level rate limiting for GitLab endpoints to reduce the impact of resource exhaustion attacks
• Configure web application firewall (WAF) rules to detect and block suspicious request patterns
• Monitor and alert on unusual resource consumption to enable rapid incident response
• Consider temporarily restricting access to GitLab for non-essential users until patching is complete

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

# Apply to GitLab location block
location / {
    limit_req zone=gitlab_limit burst=20 nodelay;
    # ... existing GitLab proxy configuration
}