A recently discovered vulnerability, CVE-2022-4255, affects all versions of GitLab Enterprise Edition (EE) ranging from 13.7 to 15.4.6, 15.5 to 15.5.5, and 15.6 to 15.6.1. This security issue involves an information leak where, surprisingly, the user's email ID is exposed via the webhook payload. As a critical component of the overall security structure of GitLab EE, addressing this issue is of high importance.

In this post, we'll discuss the technical details of CVE-2022-4255, how it can be exploited, and its potential impact on users. Links to the original references and a snippet of the problematic code will also be provided for clarity.

The CVE-2022-4255 Vulnerability

In GitLab EE, webhooks are employed to automatically trigger custom events whenever certain predefined actions take place. For instance, when a new commit is pushed to the repository or when issues are created, updated, or closed, webhooks are used to provide instant notifications.

However, in the affected versions of GitLab EE, the webhook payload that is sent out includes sensitive information such as the user's email ID. This disclosure of private email addresses leaves users susceptible to targeted phishing attacks and other malicious activities.

Here's a snippet of the code in question

class WebHookService
  def execute_hooks_for(object, event)
    web_hooks = project_web_hooks_for(object, event)
  
    if event.include? "email"
      web_hooks = web_hooks.where(include_email: true)
    end

In the code snippet above, include_email is not being properly handled, causing the user's email ID to be exposed in the webhook payload.

Original References

- GitLab Security Advisory
- GitLab Release Notes

Exploiting CVE-2022-4255

For an attacker to exploit this vulnerability, they must have access to the webhook payloads sent out by the affected GitLab EE instance. Exploiting this issue does not require administrative privileges or advanced hacking skills.

Once an attacker has access to the exposed email IDs, they have a significant advantage in launching targeted phishing campaigns or conducting social engineering attacks. This can lead to more significant security breaches like identity theft, unauthorized access to GitHub accounts, or even potential data exfiltration.

Steps to Mitigate CVE-2022-4255

GitLab has released security updates for its Enterprise Edition to address the CVE-2022-4255 vulnerability. It is critical for users to update their GitLab EE instance to the latest patched version. Here are the updates and their respective release version:

GitLab EE 15.6: Upgrade to 15.6.1

In addition to updating the GitLab EE instance, users should continuously educate and train themselves and their teams about the potential ramifications of exposed email addresses and be cautious of email communications that may appear suspicious.

Conclusion

Security researchers continuously discover vulnerabilities like CVE-2022-4255 to ensure the safety and security of the software we use daily. It is crucial for users and developers to keep abreast of these security issues and promptly apply necessary patches and updates to mitigate risks. In the case of CVE-2022-4255, users should update their GitLab EE instances as soon as possible to protect their email privacy and maintain the integrity of their workflows.

Timeline

Published on: 01/27/2023 22:15:00 UTC
Last modified on: 02/06/2023 15:01:00 UTC