Описание
Keylime Missing Authentication for Critical Function and Improper Authentication
Impact
The Keylime registrar does not enforce mutual TLS (mTLS) client certificate authentication since version 7.12.0. The registrar's TLS context is configured with ssl.CERT_OPTIONAL instead of ssl.CERT_REQUIRED, allowing any client to connect to protected API endpoints without presenting a valid client certificate.
Who is impacted:
- All Keylime deployments running versions 7.12.0 through 7.13.0
- Environments where the registrar HTTPS port (default 8891) is network-accessible to untrusted clients
What an attacker can do:
- List all registered agents (
GET /v2/agents/) - enumerate the entire agent inventory - Retrieve agent details (
GET /v2/agents/{uuid}) - obtain public TPM keys, certificates, and network locations (IP/port) of any agent - Delete any agent (
DELETE /v2/agents/{uuid}) - remove agents from the registry, disrupting attestation services
Note: The exposed TPM data (EK, AK, certificates) consists of public keys and certificates. Private keys remain protected within TPM hardware. The HMAC secret used for challenge-response validation is stored in the database but is not exposed via the API.
Affected versions: >= 7.12.0, <= 7.13.0
Fixed versions: 7.12.2, >= 7.13.1
Patches
A patch for the affected released versions is available. It removes the line that override the configuration of ssl.verify_mode, leaving the CERT_REQUIRED value set by web_util.init_mtls():
Users should upgrade to the patched version once it is released.
Workarounds
If upgrading is not immediately possible, apply one of the following mitigations:
1. Network isolation (Recommended)
Restrict access to the registrar HTTPS port (default 8891) using firewall rules to allow only trusted hosts (verifier, tenant):
Example using iptables
2. Reverse proxy with mTLS enforcement
Deploy a reverse proxy (nginx, HAProxy) in front of the registrar that enforces client certificate authentication:
Example nginx configuration
Пакеты
keylime
>= 7.12.0, < 7.12.2
7.12.2
keylime
= 7.13.0
7.13.1
9.4 Critical
CVSS3
CVE ID
9.4 Critical
CVSS3