CVE-2021-22861

Improper access control in GitHub Enterprise Server leading to unauthorized write access to forkable repositories

Description

An improper access control vulnerability was identified in GitHub Enterprise Server that allowed authenticated users of the instance to gain write access to unauthorized repositories via specifically crafted pull requests and REST API requests. An attacker would need to be able to fork the targeted repository, a setting that is disabled by default for organization owned private repositories. Branch protections such as required pull request reviews or status checks would prevent unauthorized commits from being merged without further review or validation. This vulnerability affected all versions of GitHub Enterprise Server since 2.4.21 and was fixed in versions 2.20.24, 2.21.15, 2.22.7 and 3.0.1. This vulnerability was reported via the GitHub Bug Bounty program.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.34%
Affected: GitHub GitHub Enterprise Server
Published at:
Updated at:

References

Link Tags
https://docs.github.com/en/enterprise-server%402.20/admin/release-notes#2.20.24
https://docs.github.com/en/enterprise-server%402.21/admin/release-notes#2.21.15
https://docs.github.com/en/enterprise-server%402.22/admin/release-notes#2.22.7
https://docs.github.com/en/enterprise-server%403.0/admin/release-notes#3.0.1

Frequently Asked Questions

What is the severity of CVE-2021-22861?
CVE-2021-22861 has been scored as a medium severity vulnerability.
How to fix CVE-2021-22861?
To fix CVE-2021-22861, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-22861 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-22861 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-22861?
CVE-2021-22861 affects GitHub GitHub Enterprise Server.
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