CVE-2021-39927 Server-side request forgery in GitLab

Low 3.5 Published 18 Jan 2022 Updated 4 Aug 2024

Attackers can bypass SSRF protections to access localhost services when GitLab runs on non-standard ports, potentially exposing internal data.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2021-39927?

CVE-2021-39927 is a low-severity server-side request forgery vulnerability in Gitlab Gitlab, published on 18 Jan 2022. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Server side request forgery protections in GitLab CE/EE versions between 8.4 and 14.4.4, between 14.5.0 and 14.5.2, and between 14.6.0 and 14.6.1 would fail to protect against attacks sending requests to localhost on port 80 or 443 if GitLab was configured to run on a port other than 80 or 443

Weakness: CWE-918

Which versions are affected by CVE-2021-39927?

1 open source package ship an affected version, including gitlab. It affects 1 product.

Package	Affected	Fixed in
`gitlab` Bitnami	From `8.4.0`	`14.4.5, 14.5.3, 14.6.2`

Products include Gitlab Gitlab.

How do I fix CVE-2021-39927?

Upgrade gitlab to a fixed version for your release line: 14.4.5, 14.5.3 or 14.6.2.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2021-39927 being exploited?

There is no known exploitation of CVE-2021-39927 in the wild and no public exploit code.

All Gitlab Gitlab vulnerabilities

Sources

Also known as BIT-gitlab-2021-39927, GHSA-76g9-63cr-m776, UBUNTU-CVE-2021-39927.