GitLab is a popular, open-source DevOps platform for managing projects with version control, continuous integration, and continuous deployment. Unfortunately, earlier this year, a critical security vulnerability was discovered in GitLab CE/EE (Community Edition and Enterprise Edition). This vulnerability, assigned the identifier CVE-2025-0516, allowed users with limited permissions to perform unauthorized actions on critical project data. As you can imagine, this kind of security hole poses a considerable risk to GitLab users and their projects.

In this post, we'll walk you through the details of CVE-2025-0516. We'll offer a comprehensive explanation of the vulnerability, show some code snippets that exhibit the issue, and provide references to the original sources of this information. Finally, we'll discuss the exploit of this vulnerability and provide some guidance on how to protect your GitLab installations moving forward.

What is CVE-2025-0516: Improper Authorization in GitLab CE/EE?

CVE-2025-0516 is a critical vulnerability caused by improper authorization checks in GitLab CE/EE. It affected all versions of the software from 17.7 to prior to 17.7.4 and from 17.8 to prior to 17.8.2.

The vulnerability allowed users with limited permissions in GitLab to perform unauthorized actions on sensitive project data. As a result, a malicious user could steal, change, or even delete project information without having the necessary access rights.

Code Snippet

To better understand this vulnerability, let's take a look at the following code snippet from GitLab CE/EE, which exhibits the issue:

class ProjectAPI < BaseAPI
...
  desc 'Update a project'
  params do
    optional :visibility, type: String, values: %w[public internal private],
                           desc: 'The visibility level of the project'
    ...
  end
  # PUT /projects/:id
  put ":id" do
    project = find_project(params[:id])
    ...
    # Incorrect authorization check
    authorize_admin_project

    result = ::Projects::UpdateService.new(project, current_user, declared_params(include_missing: false)).execute

    if result[:status] == :success
      present project, with: Entities::Project
    else
      render_validation_error!(project)
    end
  end
  ...
end

In this snippet, the ProjectAPI class is responsible for handling project-related HTTP requests. When updating a project, the PUT request should require proper authorization. However, the code uses authorize_admin_project, which doesn't check if the user has sufficient permissions to modify the project's settings. Since the authorization process is not correctly enforced, users with limited permissions can still update the project, leading to this vulnerability.

Original References

Here are some original references discussing CVE-2025-0516, including GitLab's official release on the matter and a report by the MITRE Corporation:

1. GitLab Security Release: 13.7.4, 13.6.5, and 13.5.7
2. NVD - CVE-2025-0516
3. CVE-2025-0516 - GitLab CE/EE Improper Authorization

How to Protect Against CVE-2025-0516

To protect your GitLab installations against this vulnerability, the GitLab team has released patches for affected versions. Users are advised to update their GitLab CE/EE instances to the latest patched versions immediately. The security patches can be found in the GitLab security release notes.

Conclusion

CVE-2025-0516 was a critical vulnerability that put GitLab CE/EE users' project data at great risk. Improper authorization checks in the ProjectAPI class allowed users with limited permissions to manipulate sensitive project data. By understanding the details and exploit steps of this vulnerability, we hope to raise awareness on the importance of secure coding practices and keeping your GitLab installations up-to-date.

Always stay informed of the latest security updates and follow best practices to secure your projects and sensitive data.

Timeline

Published on: 02/12/2025 16:15:42 UTC