An issue has been discovered in GitLab CE/EE affecting all versions starting from 10.6 prior to 16.9.7, starting from 16.10 prior to 16.10.5, and starting from 16.11 prior to 16.11.2 in which cross-site request forgery may have been possible on GitLab instances configured to use JWT as an OmniAuth provider.
Weakness
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Gitlab |
Gitlab |
10.6.0 (including) |
16.9.7 (excluding) |
| Gitlab |
Gitlab |
16.10.0 (including) |
16.10.5 (excluding) |
| Gitlab |
Gitlab |
16.11.0 (including) |
16.11.2 (excluding) |
| Gitlab |
Ubuntu |
esm-apps/xenial |
* |
| Gitlab |
Ubuntu |
upstream |
* |
Potential Mitigations
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
- For example, use anti-CSRF packages such as the OWASP CSRFGuard. [REF-330]
- Another example is the ESAPI Session Management control, which includes a component for CSRF. [REF-45]
- Use the “double-submitted cookie” method as described by Felten and Zeller:
- When a user visits a site, the site should generate a pseudorandom value and set it as a cookie on the user’s machine. The site should require every form submission to include this value as a form value and also as a cookie value. When a POST request is sent to the site, the request should only be considered valid if the form value and the cookie value are the same.
- Because of the same-origin policy, an attacker cannot read or modify the value stored in the cookie. To successfully submit a form on behalf of the user, the attacker would have to correctly guess the pseudorandom value. If the pseudorandom value is cryptographically strong, this will be prohibitively difficult.
- This technique requires Javascript, so it may not work for browsers that have Javascript disabled. [REF-331]
References