MarbleRun unauthenticated recovery allows Coordinator impersonation

Impact

During recovery, a Coordinator only verifies that a given recovery key decrypts the sealed state, not if this key was provided by a party with access to one of the recovery keys defined in the manifest. This allows an attacker to manually craft a sealed state using their own recovery keys, and a manifest that does not match the rest of the state.

If network traffic is redirected from the legitimate coordinator to the attacker's Coordinator, a remote party is susceptible to impersonation if they verify the Coordinator without comparing the root certificate of the Coordinator against a trusted reference.

Under these circumstances, an attacker can trick a remote party into trusting the malicious Coordinator by presenting a manifest that does not match the actual state of the deployment.

This issue does not affect the following:

• secrets and state of the legitimate Coordinator instances
• integrity of workloads
• certificates chaining back to the legitimate Coordinator root certificate

Patches

The issue has been patched in v1.7.0.

Workarounds

Connections that purely authenticate based on a known Coordinator's root certificate, e.g. the one retrieved when using the marblerun manifest set CLI command, are not affected.