CVE-2023-4011: GitLab EE Vulnerability Discovered - Watch Out for DoS Attack Due to Resource Spike

Hello folks! Today, we're going to dive deep into an important security issue that has been discovered in GitLab EE - a popular enterprise web application used for version control and CI/CD pipelines. The vulnerability, identified as CVE-2023-4011, affects all versions of the software ranging from 15.11 to those prior to 16.2.2. In essence, this vulnerability allows an attacker to spike resource consumption, leading to a Denial of Service (DoS) attack.

Before we continue, it's worth noting that this issue doesn't affect GitLab Community Edition (CE). If you are using GitLab EE, however, read on and learn how to protect yourself.

Understanding the Vulnerability

The vulnerability in question revolves around an attacker being able to intentionally spike the resource consumption on the target GitLab EE system. When resource consumption reaches a certain threshold, it results in a DoS attack. DoS attacks are aimed at affecting the availability of a system, making it difficult or even impossible for legitimate users to access or use the targeted resource.

Exploit Details

While the specifics of the exploit haven't been disclosed entirely to prevent misuse, researchers do note that the attacker sends malformed requests to the vulnerable GitLab EE instance. These requests trigger an abnormal behavior in the system, causing the resource consumption to spike unexpectedly. The increased load takes a toll on the overall performance and availability of the GitLab EE installation.

Code Snippet of the Attack

While we may not have the precise code to exploit the vulnerability, below is a snippet that demonstrates how an attacker could flood your GitLab EE instance with bogus requests:

import requests

target_url = "https://<your-gitlab-instance>/";
malformed_request_payload = {
    # specific malformed request details
}

for _ in range(100000):  # adjust the number of requests as needed
    requests.post(target_url, data=malformed_request_payload)

*Note: This snippet is provided for educational purposes only and is not intended for malicious use. Misuse can result in legal consequences.

References and Official Announcements

In order to stay informed and up to date with the latest information regarding this vulnerability, be sure to keep an eye on the official GitLab security advisory:
- GitLab Security Advisory

Also, refer to the official CVE detailing this vulnerability

- CVE-2023-4011

How to Protect Your GitLab EE Installation

The best way to protect your GitLab EE instance from this vulnerability is to update your software to the latest and secure version, which in this case is 16.2.2 or later. GitLab has released patches addressing this vulnerability, so make sure your installation is up to date.

# Steps to update your GitLab EE installation:
$ sudo apt update
$ sudo apt install gitlab-ee

Once you've completed the update, make sure to confirm that your GitLab EE installation shows the correct software version.

Conclusion

This recent GitLab EE vulnerability, identified as CVE-2023-4011, poses a serious threat to the availability of your GitLab EE instance due to the potential of DoS attacks. We highly recommended that you take the necessary precautions and update your software to the latest secure version, 16.2.2 or later. Stay vigilant and stay safe out there!

Timeline

Published on: 08/02/2023 06:15:00 UTC
Last modified on: 08/04/2023 19:45:00 UTC