In this post, we will discuss the stored cross-site scripting (XSS) vulnerability found in Jenkins Docker Swarm Plugin 1.11 and earlier, identified as CVE-2023-40350. The vulnerability arises because values returned from Docker are not properly escaped before being inserted into the Docker Swarm Dashboard view. We will analyze the cause and possible exploitation scenarios, provide code snippets, and links to original references.

Vulnerability Details

Jenkins is a widely used open-source automation server that can be extended with plugins to integrate various tools and platforms. The Docker Swarm Plugin is one such extension that allows Jenkins to interact with Docker Swarm clusters for automating tasks.

The vulnerability exists due to insufficient input validation in the plugin, which fails to properly escape values returned from Docker before inserting them into the Docker Swarm Dashboard view. This enables attackers to inject malicious scripts into the application, potentially leading to compromised user sessions or unauthorized actions performed on behalf of targeted users.

Exploit Details

To exploit this vulnerability, an attacker needs to be able to control responses from Docker. This can be achieved by compromising a vulnerable Docker host or using a man-in-the-middle (MITM) attack to intercept and modify Docker API responses.

The following code snippet demonstrates a potential payload that an attacker could inject into a Docker API response:

<script>alert('XSS')</script>

When this payload is returned as part of a Docker API response, the Jenkins Docker Swarm plugin would not escape this script before inserting it into the Docker Swarm Dashboard view. Consequently, users visiting the dashboard would have the attacker's script executed in their browser context, leading to a stored XSS attack.

Mitigation and Remediation

The issue has been addressed in Jenkins Docker Swarm Plugin version 1.12, where proper input validation and escaping have been implemented. Users of Jenkins and the Docker Swarm Plugin are strongly advised to update their plugin version to 1.12 or later to ensure that their systems are no longer vulnerable to this specific attack vector.

Original References

1. Jenkins Security Advisory
2. CVE-2023-40350 - National Vulnerability Database (NIST)

Conclusion

In conclusion, the CVE-2023-40350 vulnerability in Jenkins Docker Swarm Plugin 1.11 and earlier presents a significant threat to users, allowing attackers to execute malicious scripts in their browser context. It is essential to update the plugin to version 1.12 or later to mitigate the risk posed by this vulnerability. Stay informed about security issues in the software you use, and always apply patches and updates in a timely manner to ensure the security of your systems.

Timeline

Published on: 08/16/2023 15:15:00 UTC
Last modified on: 08/18/2023 19:56:00 UTC