CVE-2022-1053: 
Python vulnerability analysis and mitigation

CVE-2022-1053 is a security vulnerability in Keylime, an open-source TPM software for Bootstrapping and Maintaining Trust. The vulnerability was discovered and disclosed in May 2022, affecting Keylime versions prior to 6.4.0. The issue impacts the validation process between the tenant and verifier components of the system (NVD).

The vulnerability stems from Keylime's failure to enforce consistency in agent registrar data validation between the tenant and verifier components. When the tenant validates the EK and identity quote, and the verifier validates the integrity quote, there is no enforcement ensuring they use the same registrar data. This implementation flaw has been assigned a CVSS v3.1 base score of 9.1 (CRITICAL) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N (NVD).

The vulnerability allows an attacker to use one AK (Attestation Key) and EK (Endorsement Key) pair from a real TPM to pass EK validation while providing the verifier with an AK from a software TPM. This breaks the entire chain of trust as the verifier uses an unvalidated AK. The issue becomes more severe when validation occurs before the agent is added to the verifier, as the timing is easier and the verifier doesn't validate if the regcount entry equals 1 (NVD).

The vulnerability has been fixed in Keylime version 6.4.0. Users are strongly advised to upgrade to this version or later. The fix involves changes to how the tenant provides the AK and mTLS certificate, eliminating the need for the verifier to connect to the registrar (Fedora Update).