CVE-2025-0765: GitLab Auth Bypass Vulnerability

CVE-2025-0765 Overview

An improper authorization vulnerability has been discovered in GitLab CE/EE that allows unauthorized users to access custom service desk email addresses. This vulnerability affects all versions from 17.9 before 18.0.5, 18.1 before 18.1.3, and 18.2 before 18.2.1. The flaw stems from insufficient access controls (CWE-863) that fail to properly validate user permissions when accessing service desk configuration data.

Critical Impact

Unauthorized disclosure of custom service desk email addresses could enable targeted phishing attacks, social engineering campaigns, or reconnaissance activities against organizations using GitLab's service desk functionality.

Affected Products

• GitLab Community Edition (CE) versions 17.9 to 18.0.4
• GitLab Enterprise Edition (EE) versions 17.9 to 18.0.4
• GitLab CE/EE versions 18.1 to 18.1.2
• GitLab CE/EE version 18.2 (prior to 18.2.1)

Discovery Timeline

• 2025-07-24 - CVE-2025-0765 published to NVD
• 2025-08-08 - Last updated in NVD database

Technical Details for CVE-2025-0765

Vulnerability Analysis

This vulnerability is classified as Improper Authorization (CWE-863), where the application fails to properly verify that a user has the required permissions before allowing access to sensitive service desk email address information. The flaw exists in the authorization logic that governs access to custom service desk configuration data within GitLab projects.

GitLab's service desk feature allows teams to create custom email addresses for receiving support tickets directly into GitLab issues. Under normal circumstances, these email addresses should only be visible to users with appropriate project permissions. However, due to the authorization bypass, users with low-level privileges can enumerate and retrieve these custom email addresses without proper authorization checks.

Root Cause

The root cause of this vulnerability lies in missing or inadequate authorization checks in the code path that handles requests for service desk email address information. The application does not properly enforce access controls, allowing authenticated users with minimal privileges to query and retrieve custom service desk email addresses that should be restricted to project administrators or maintainers.

This type of authorization flaw typically occurs when developers assume that hiding UI elements is sufficient security, without implementing proper server-side authorization validation. The vulnerability was reported through GitLab's HackerOne bug bounty program, as documented in HackerOne Report #2956315.

Attack Vector

The attack is network-based and requires low-privilege authentication to the GitLab instance. An attacker with a valid GitLab account can exploit this vulnerability by making crafted API requests or navigating to specific endpoints that expose service desk email configuration data without proper authorization verification.

The attack flow involves:

1. An attacker authenticates to a vulnerable GitLab instance with any valid user account
2. The attacker identifies target projects using GitLab's service desk feature
3. By accessing specific endpoints or API calls, the attacker bypasses authorization checks
4. Custom service desk email addresses are disclosed to the unauthorized user

For technical details about this vulnerability, refer to GitLab Issue #515381.

Detection Methods for CVE-2025-0765

Indicators of Compromise

• Unusual API requests to service desk configuration endpoints from users without project maintainer or admin roles
• Audit log entries showing access to project service desk settings by unauthorized users
• Multiple failed or successful attempts to enumerate service desk email addresses across different projects
• Anomalous access patterns to project settings endpoints from accounts with limited permissions

Detection Strategies

• Monitor GitLab audit logs for unauthorized access to service desk configuration endpoints
• Implement alerting on API requests to service desk email retrieval endpoints from users without appropriate project roles
• Review access logs for patterns indicating systematic enumeration of project service desk configurations
• Deploy application-layer monitoring to detect attempts to bypass authorization controls

Monitoring Recommendations

• Enable comprehensive audit logging in GitLab to capture all service desk configuration access events
• Configure SIEM rules to alert on access to sensitive project settings by users without maintainer or higher permissions
• Implement rate limiting and anomaly detection for API endpoints related to service desk functionality
• Regularly review user access patterns to identify potential unauthorized data access attempts

How to Mitigate CVE-2025-0765

Immediate Actions Required

• Upgrade GitLab CE/EE to version 18.0.5, 18.1.3, or 18.2.1 or later immediately
• Audit service desk email addresses that may have been exposed and consider rotating them if sensitive
• Review GitLab audit logs to identify any potential unauthorized access to service desk configurations
• Implement network-level access controls to limit who can access the GitLab instance while patching is in progress

Patch Information

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

• GitLab 18.0.5 for the 18.0.x branch
• GitLab 18.1.3 for the 18.1.x branch
• GitLab 18.2.1 for the 18.2.x branch

The patches implement proper authorization checks to ensure only users with appropriate permissions can access service desk email configuration data. For more information, see GitLab Issue #515381.

Workarounds

• Restrict network access to GitLab instances to trusted IP ranges until patches can be applied
• Review and minimize the number of users with authenticated access to the GitLab instance
• Consider temporarily disabling service desk functionality for sensitive projects if immediate patching is not possible
• Implement additional monitoring and alerting on service desk configuration access

# Check current GitLab version
gitlab-rake gitlab:env:info

# Upgrade GitLab to patched version (example for Omnibus installation)
apt-get update && apt-get install gitlab-ce=18.0.5-ce.0

# Verify upgrade was successful
gitlab-rake gitlab:check