Checks whether a container has unmasked access to the host’s /proc filesystem, which allows retrieval of sensitive information and could permit changing kernel parameters at runtime. The rule verifies that kubernetes_pod_security_policy.spec.allowed_proc_mount_types does not contain the value Unmasked and that allowed_proc_mount_types includes Default as the expected value. Unmasked access to /proc increases the attack surface and can enable privilege escalation or other runtime compromises.