A new security vulnerability (CVE-2023-5963) has been discovered in GitLab Enterprise Edition. This issue affects all versions ranging from 13.9 to 16.3.6, 16.4 prior to 16.4.2, and 16.5 prior to 16.5.1. The vulnerability specifically targets the Advanced Search function in GitLab EE and could lead to denial of service (DoS) attacks by exploiting the improper handling of syntax operators.

Exploit Details

The vulnerability resides in the Advanced Search feature of GitLab EE. An attacker could exploit this issue by chaining a large number of syntax operators, thus causing the application to become unresponsive and lead to a denial of service.

Consider the following code snippet that demonstrates the issue

# This is an example of a malicious search query that could lead to a DoS attack
search_query = "test" + " OR " * 10000 + "example"

In this example, the Python code above generates a search query that consists of a series of 'OR' operators. When this malicious search query is submitted to GitLab EE's Advanced Search function, the application may become unresponsive due to the large number of chained syntax operators. The vulnerability occurs because GitLab does not properly handle or limit the number of syntax operators present in a search query.

Original References and Resources

To get more information and technical details about this vulnerability, please refer to the following resources:

1. GitLab Official Security Advisory: GitLab Security Release: 12.10.4, 13..4, and 13.1.4
2. NVD - National Vulnerability Database: CVE-2023-5963 Detail
3. MITRE CVE Dictionary: CVE-2023-5963

Mitigation and Workarounds



It is strongly recommended that you update your GitLab EE deployment to a patched version as soon as possible to avoid any potential threats and keep your system secure.

You can refer to GitLab's official upgrade guide to make the necessary updates: Upgrading GitLab


In conclusion, the CVE-2023-5963 vulnerability in GitLab EE's Advanced Search function could lead to denial of service attacks due to the improper handling and limitation of syntax operators. It is important to keep your GitLab EE deployment up-to-date with the latest patched versions to ensure the overall security and prevent any threats to your system.


Published on: 11/06/2023 13:15:10 UTC
Last modified on: 11/14/2023 17:51:28 UTC