PYSEC-2026-2548: Keylime: keylime: security bypass due to hardcoded tpm quote nonce
A flaw was found in Keylime. An attacker with root access on an enrolled monitored machine, where the Keylime agent runs, can exploit a vulnerability in the Keylime verifier. The verifier uses a hardcoded challenge nonce for Trusted Platform Module (TPM) quote attestation instead of a cryptographically random value. This allows the attacker to stockpile valid TPM quotes and replay them to evade detection after compromising the system. This issue affects only the push model deployment.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
Only Keylime deployments using the push model are affected. The issue applies to enrolled monitored machines on which the Keylime agent runs.
What access does an attacker need to exploit the flaw?
The attacker needs root access on an enrolled monitored machine running the Keylime agent. They can then collect valid TPM quotes and replay them after compromising the system.
What is the practical impact of a successful exploit?
A successful attacker can evade verifier detection by replaying previously stockpiled valid TPM attestation quotes. This can make a compromised monitored machine appear to pass attestation.