Linkerd potential access to the shutdown endpoint

Vulnerability Description

Linkerd is an open source, ultralight, security-first service mesh for Kubernetes. In affected versions when the application being run by linkerd is susceptible to SSRF, an attacker could potentially trigger a denial-of-service (DoS) attack by making requests to localhost:4191/shutdown. Linkerd could introduce an optional environment variable to control a token that must be passed as a header. Linkerd should reject shutdown requests that do not include this header. This issue has been addressed in release version edge-24.6.2 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

References

• https://github.com/linkerd/linkerd2/security/advisories/GHSA-6v94-gj6x-jqj7
• https://github.com/linkerd/linkerd2/commit/35fb2d6d11ef6520ae516dd717790529f85224fa
• https://github.com/linkerd/linkerd2-proxy/blob/46957de49f25fd4661af7b7c52659148f4d6dd27/linkerd/app/admin/src/server.rs