CVE-2021-22862 Improper access control in GitHub Enterprise Server leading to the disclosure of Actions secrets to forks

Medium 6.5 Published 3 Mar 2021 Updated 3 Aug 2024

Authenticated users can bypass fork restrictions to disclose Actions secrets from parent repositories via manipulated pull request references.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-22862?

CVE-2021-22862 is a medium-severity missing authorization vulnerability in GitHub Enterprise Server, published on 3 Mar 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

An improper access control vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user with the ability to fork a repository to disclose Actions secrets for the parent repository of the fork. This vulnerability existed due to a flaw that allowed the base reference of a pull request to be updated to point to an arbitrary SHA or another pull request outside of the fork repository. By establishing this incorrect reference in a PR, the restrictions that limit the Actions secrets sent a workflow from forks could be bypassed. This vulnerability affected GitHub Enterprise Server version 3.0.0, 3.0.0.rc2, and 3.0.0.rc1. This vulnerability was reported via the GitHub Bug Bounty program.

Weakness: CWE-285

Which versions are affected by CVE-2021-22862?

It affects 1 product.

Products include Github Github.

How do I fix CVE-2021-22862?

No fix has been published for CVE-2021-22862 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2021-22862 being exploited?

There is no known exploitation of CVE-2021-22862 in the wild and no public exploit code.

Sources

Also known as GHSA-2xwj-g27r-p9cr.