Argo CD repo-server Denial of Service vulnerability

Impact

All versions of ArgoCD starting from v2.4 have a bug where the ArgoCD repo-server component is vulnerable to a Denial-of-Service attack vector. Specifically, the said component extracts a user-controlled tar.gz file without validating the size of its inner files. As a result, a malicious, low-privileged user can send a malicious tar.gz file that exploits this vulnerability to the repo-server, thereby harming the system's functionality and availability. Additionally, the repo-server is susceptible to another vulnerability due to the fact that it does not check the extracted file permissions before attempting to delete them. Consequently, an attacker can craft a malicious tar.gz archive in a way that prevents the deletion of its inner files when the manifest generation process is completed.

Patches

A patch for this vulnerability has been released in the following Argo CD versions:

• v2.6.15
• v2.7.14
• v2.8.3

Workarounds

The only way to completely resolve the issue is to upgrade.

Mitigations

Configure RBAC (Role-Based Access Control) and provide access for configuring applications only to a limited number of administrators. These administrators should utilize trusted and verified Helm charts.

For more information

If you have any questions or comments about this advisory:

• Open an issue in the Argo CD issue tracker or discussions
• Join us on Slack in channel #argo-cd

Credits

This vulnerability was found & reported by GE Vernova – Amit Laish.

The Argo team would like to thank these contributors for their responsible disclosure and constructive communications during the resolve of this issue