Argo CD is Vulnerable to Unauthenticated Remote DoS via malformed Azure DevOps git.push webhook

Vulnerability Description

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. For versions 2.9.0-rc1 through 2.14.19, 3.0.0-rc1 through 3.2.0-rc1, 3.1.6 and 3.0.17, when the webhook.azuredevops.username and webhook.azuredevops.password are not set in the default configuration, the /api/webhook endpoint crashes the entire argocd-server process when it receives an Azure DevOps Push event whose JSON array resource.refUpdates is empty. The slice index [0] is accessed without a length check, causing an index-out-of-range panic. A single unauthenticated HTTP POST is enough to kill the process. This issue is resolved in versions 2.14.20, 3.2.0-rc2, 3.1.8 and 3.0.19.

References

• https://github.com/argoproj/argo-cd/security/advisories/GHSA-gpx4-37g2-c8pv
• https://github.com/argoproj/argo-cd/commit/1a023f1ca7fe4ec942b4b6696804988d5a632baf