CVE-2025-2408: GitLab Auth Bypass Vulnerability

CVE-2025-2408 Overview

CVE-2025-2408 is an access control weakness in GitLab Community Edition (CE) and Enterprise Edition (EE). The flaw affects all versions from 13.12 before 17.8.7, 17.9 before 17.9.6, and 17.10 before 17.10.4. Under specific conditions, authenticated or unauthenticated users can bypass IP-based access restrictions and view sensitive information intended to be gated by network controls. The issue is tracked as [CWE-1220] (Insufficient Granularity of Access Control) and was disclosed through GitLab's HackerOne program. GitLab has released patched versions across the three affected release branches.

Critical Impact
Attackers can bypass configured IP allowlists on GitLab instances and read sensitive project or group information without originating from an approved network range.

Affected Products

GitLab Community Edition versions 13.12 through 17.8.6
GitLab Enterprise Edition versions 17.9 through 17.9.5
GitLab CE/EE versions 17.10 through 17.10.3

Discovery Timeline

2025-04-10 - CVE-2025-2408 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-2408

Vulnerability Analysis

CVE-2025-2408 is an authorization bypass affecting GitLab's IP access restriction feature. Administrators use this feature to limit access to groups, projects, and sensitive endpoints based on source IP address ranges. The vulnerability allows requests originating from non-approved IP addresses to reach protected resources under certain conditions. The confidentiality impact is limited to disclosure of sensitive information, with no direct impact on integrity or availability. The flaw is exploitable over the network without prior authentication or user interaction. EPSS data lists a probability of 0.301% for near-term exploitation activity.

Root Cause

The root cause is insufficient granularity in the access control checks that enforce IP allowlists. Certain request paths within GitLab do not consistently evaluate the configured IP restriction policy before returning sensitive data. As a result, the enforcement layer treats some flows as exempt from the network-level allowlist, weakening the intended defense-in-depth boundary. The classification under [CWE-1220] reflects that authorization decisions are made without sufficient checks against the required IP context.

Attack Vector

An attacker sends crafted HTTPS requests to a GitLab instance that has IP access restrictions configured on a group or project. By targeting endpoints where the IP check is not applied, the attacker retrieves information that should only be accessible from approved networks. Exploitation requires network reachability to the GitLab web tier but no valid credentials or user interaction. This makes internet-exposed GitLab deployments the highest-risk targets, particularly those relying on IP restrictions as a primary control for regulated data.

See the GitLab Issue Report #525323 and the HackerOne Security Report #3027775 for additional technical context. No public proof-of-concept code is available at this time.

Detection Methods for CVE-2025-2408

Indicators of Compromise

Successful HTTP 200 responses to GitLab API or web endpoints originating from source IPs outside configured allowlists for a given group or project.
Access logs showing repeated enumeration of group, project, or namespace endpoints from unfamiliar geographies or hosting providers.
Discrepancies between GitLab audit events (access granted) and network-level ACLs (source IP not permitted).

Detection Strategies

Correlate GitLab production logs (production_json.log, api_json.log) with the source IP allowlist policy to identify requests that should have been blocked.
Alert on anonymous or low-privilege sessions accessing endpoints tied to groups with ip_restriction_ranges configured.
Review audit events for group_ip_restriction policy hits and confirm enforcement decisions match policy intent.

Monitoring Recommendations

Forward GitLab web, API, and audit logs to a centralized analytics platform and baseline access patterns per group.
Monitor egress from GitLab to external artifact registries or clone destinations that do not match the expected user population.
Track version banners on GitLab instances to identify hosts that have not been upgraded to the patched releases.

How to Mitigate CVE-2025-2408

Immediate Actions Required

Upgrade self-managed GitLab instances to 17.8.7, 17.9.6, or 17.10.4 or later without delay.
Inventory all groups and projects that rely on IP access restrictions and assume sensitive data disclosure until logs are reviewed.
Rotate any secrets, tokens, or credentials that may have been readable through the affected endpoints during the exposure window.

Patch Information

GitLab has released fixed versions 17.8.7, 17.9.6, and 17.10.4 addressing CVE-2025-2408. GitLab.com is already running the patched code. Administrators of self-managed instances should apply the upgrade following the standard omnibus or Helm chart upgrade procedure and validate that IP restrictions are enforced across all affected endpoints after deployment.

Workarounds

Enforce IP restrictions at a network layer using a reverse proxy, load balancer, or Web Application Firewall in front of GitLab.
Restrict GitLab exposure to a VPN or zero-trust network segment until patched versions are deployed.
Disable or reduce the scope of features that depend solely on GitLab's built-in IP allowlists for regulated data.

bash

# Example NGINX reverse proxy IP allowlist enforced independently of GitLab
location / {
    allow 10.0.0.0/8;
    allow 192.0.2.0/24;
    deny  all;
    proxy_pass http://gitlab_upstream;
}