Improper access control allows admin privilege escalation in Argo CD

Vulnerability Description

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. All unpatched versions of Argo CD starting with 1.0.0 are vulnerable to an improper access control bug, allowing a malicious user to potentially escalate their privileges to admin-level. Versions starting with 0.8.0 and 0.5.0 contain limited versions of this issue. To perform exploits, an authorized Argo CD user must have push access to an Application's source git or Helm repository or `sync` and `override` access to an Application. Once a user has that access, different exploitation levels are possible depending on their other RBAC privileges. A patch for this vulnerability has been released in Argo CD versions 2.3.2, 2.2.8, and 2.1.14. Some mitigation measures are available but do not serve as a substitute for upgrading. To avoid privilege escalation, limit who has push access to Application source repositories or `sync` + `override` access to Applications; and limit which repositories are available in projects where users have `update` access to Applications. To avoid unauthorized resource inspection/tampering, limit who has `delete`, `get`, or `action` access to Applications.

References

• https://github.com/argoproj/argo-cd/security/advisories/GHSA-2f5v-8r3f-8pww
• https://github.com/argoproj/argo-cd/commit/af03b291d4b7e9d3ce9a6580ae9c8141af0e05cf
• https://github.com/argoproj/argo-cd/releases/tag/v2.1.14
• https://github.com/argoproj/argo-cd/releases/tag/v2.2.8
• https://github.com/argoproj/argo-cd/releases/tag/v2.3.2