CVE-2012-4546 in Red Hat
Summary
by MITRE
The default configuration for IPA servers in Red Hat Enterprise Linux 6, when revoking a certificate from an Identity Management replica, does not properly update another Identity Management replica, which causes inconsistent Certificate Revocation Lists (CRLs) to be used and might allow remote attackers to bypass intended access restrictions via a revoked certificate.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/29/2024
The vulnerability described in CVE-2012-4546 represents a critical inconsistency in the Identity Management (IdM) infrastructure of Red Hat Enterprise Linux 6 systems. This flaw specifically affects the Certificate Revocation List (CRL) synchronization mechanism within the Identity Management server architecture, where the default configuration fails to properly propagate certificate revocation information across replica servers. The issue stems from the improper handling of certificate revocation updates in distributed environments where multiple IPA replicas maintain synchronized copies of the directory service and certificate management data. When a certificate is revoked on one replica, the system does not correctly ensure that all other replicas receive and apply the updated CRL information, creating a window of opportunity for security exploitation.
The technical root cause of this vulnerability lies in the replication synchronization mechanism that governs how certificate status changes are propagated throughout the IdM infrastructure. This flaw operates at the system configuration level rather than as a code-level vulnerability, making it particularly dangerous because it affects the fundamental trust model of the certificate management system. The default settings in RHEL 6's IPA server implementation do not enforce proper consistency checks or synchronization protocols when certificate revocation events occur, leading to scenarios where some replicas maintain outdated CRL information while others have received the updated revocation data. This inconsistency creates a race condition where revoked certificates may still be accepted by systems that have not yet received the updated CRL information, effectively allowing attackers to bypass authentication and access controls.
The operational impact of this vulnerability extends beyond simple certificate validation failures and represents a significant threat to the integrity of the entire Identity Management system. Attackers who can exploit this inconsistency may leverage the time gap between when a certificate is revoked on one replica and when other replicas receive the update to continue using the revoked certificate for authentication purposes. This scenario directly violates the core security principle of certificate-based authentication and could enable unauthorized access to protected resources, privilege escalation, and potential lateral movement within networks that rely on IPA for identity management. The vulnerability affects the availability and integrity of the authentication system, as legitimate certificate revocation procedures become ineffective due to the distributed nature of the problem.
Security professionals should consider this vulnerability in the context of the broader ATT&CK framework, particularly under the techniques related to credential access and privilege escalation. The flaw aligns with tactics that involve exploiting configuration weaknesses in authentication systems, and represents a failure in the principle of least privilege enforcement. Organizations using RHEL 6 IPA servers must implement immediate mitigations including manual synchronization of CRL information across all replicas, implementation of monitoring solutions to detect CRL inconsistencies, and potentially disabling the affected default configuration until proper updates or patches are applied. The vulnerability also highlights the importance of proper configuration management and the need for robust replication protocols in distributed identity systems. From a compliance perspective, this issue would likely violate standards such as NIST SP 800-53 controls related to access control and audit logging, as it creates potential security gaps that could be exploited by malicious actors. Organizations should also consider implementing additional monitoring and alerting mechanisms to detect when certificate revocation events are not properly propagated throughout their IPA infrastructure.