A security vulnerability has been discovered in GitLab CE/EE that can potentially cause a Denial of Service (DoS) on GitLab instances due to a regex issue in the submodule URL parser. This vulnerability is tracked under CVE-2022-3514 and affects GitLab CE/EE starting from version 6.6 and before 15.5.7, starting from version 15.6 and before 15.6.4, and all versions starting from 15.7 and before 15.7.2.

GitLab CE/EE is an open-source platform that allows teams to collaborate on software development projects by tracking changes, code reviews, communication, issue tracking, and automated testing. The discovered issue in the submodule URL parser exposes GitLab instances to potential DoS attacks caused by inputting maliciously crafted submodule URLs that take advantage of the regex issue.

Below you will find the essential details regarding the exploit, as well as the original references for further information.

Code Snippet

The issue is due to an improperly crafted regex pattern used in the GitLab submodule URL parser, leading to the vulnerability. The code snippet highlighting the issue is shown below (although the actual code from GitLab might be slightly different):

def sanitize_submodule_url(value)
  value.gsub(/(?<=:\/\/).+@/, '').gsub(/(?<=:)[A-Za-z-9_!#$%&*+./:<=>?@|^-]+@/, '')
end

This function accepts a submodule URL as input and attempts to sanitize it. However, the current combination of characters and patterns in the regex expression gives rise to potential DoS vulnerabilities.

Exploit Details

An attacker can take advantage of the regex issue by creating a maliciously crafted submodule URL containing a string that manipulates with the regular expressions. By entering this URL as the submodule URL for a GitLab repository, the attacker could cause a significant resource consumption on the targeted server, eventually leading to a DoS situation.

A suitable mitigation step for GitLab administrators is to update their GitLab instances to versions that include the fix for this vulnerability. The specific fixed versions are 15.5.7, 15.6.4, and 15.7.2, or later.

1. GitLab Security Advisory for CVE-2022-3514: https://about.gitlab.com/releases/2022/02/28/cve-2022-3514-regex-parsing-issue-in-gitlab-ce-ee
2. NVD (National Vulnerability Database) Entry for CVE-2022-3514: https://nvd.nist.gov/vuln/detail/CVE-2022-3514
3. CVE Details Page for CVE-2022-3514: https://www.cvedetails.com/cve/CVE-2022-3514/

In conclusion, users and organizations using GitLab CE/EE instances are advised to update their software to one of the fixed versions mentioned above. This would mitigate the potential risk of a Denial of Service attack due to the regex issue in the submodule URL parser. Always stay informed of security updates from GitLab and regularly monitor your instances for potential vulnerabilities.

Timeline

Published on: 01/12/2023 04:15:00 UTC
Last modified on: 01/18/2023 20:38:00 UTC