CVE-2013-0199 in FreeIPA
Summary
by MITRE
The default LDAP ACIs in FreeIPA 3.0 before 3.1.2 do not restrict access to the (1) ipaNTTrustAuthIncoming and (2) ipaNTTrustAuthOutgoing attributes, which allow remote attackers to obtain the Cross-Realm Kerberos Trust key via unspecified vectors.
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Analysis
by VulDB Data Team • 03/22/2022
The vulnerability identified as CVE-2013-0199 represents a critical access control flaw within the FreeIPA directory service infrastructure that affects versions prior to 3.1.2. This issue specifically targets the Lightweight Directory Access Protocol implementation within FreeIPA's authentication and authorization framework, where default Access Control Instructions (ACIs) fail to properly restrict access to sensitive attribute data. The flaw manifests in the improper configuration of access controls for two critical attributes: ipaNTTrustAuthIncoming and ipaNTTrustAuthOutgoing, which are essential components in cross-realm Kerberos trust relationships. These attributes contain cryptographic keys and authentication data that should remain protected from unauthorized access.
The technical implementation of this vulnerability stems from the default LDAP ACI configuration that does not adequately enforce restrictions on sensitive attribute access within the FreeIPA directory service. When the system initializes, it establishes default access controls that are insufficiently restrictive, allowing any authenticated user or potentially unauthenticated attacker to access the specified attributes through LDAP queries. The vulnerability is classified under CWE-284 Access Control Flaws, specifically addressing insufficient access control mechanisms that permit unauthorized access to sensitive data. This weakness enables attackers to exploit the directory service's authentication infrastructure by leveraging the exposed trust attributes to extract Cross-Realm Kerberos Trust keys, which are fundamental to establishing secure cross-domain authentication relationships.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally compromises the security of cross-realm trust relationships within the Kerberos authentication framework. Attackers who successfully exploit this vulnerability can obtain the cryptographic keys used in Kerberos trust relationships, potentially enabling them to establish unauthorized trust relationships between domains, perform credential theft, or execute advanced attacks such as pass-the-ticket or Kerberoasting attacks. This weakness directly impacts the integrity and confidentiality of the authentication infrastructure, as the exposed trust keys could be used to impersonate users across trusted domains or gain unauthorized access to systems that rely on cross-realm authentication. The vulnerability affects organizations using FreeIPA for identity management and authentication, particularly those with cross-domain trust relationships, making it a significant concern for enterprise security infrastructure.
Mitigation strategies for this vulnerability must address both the immediate configuration issues and implement broader security controls to prevent unauthorized access to sensitive directory attributes. Organizations should immediately upgrade to FreeIPA version 3.1.2 or later, which contains the patched ACI configurations that properly restrict access to the vulnerable attributes. System administrators must also conduct thorough audits of existing LDAP ACI configurations to ensure that no other attributes are exposed through similar misconfigurations. The implementation should follow ATT&CK technique T1078 Valid Accounts, where adversaries may use legitimate credentials to access systems, but in this case, the vulnerability allows unauthorized access through the directory service itself. Additional protective measures include implementing network segmentation to limit LDAP access, configuring more restrictive access controls for sensitive attributes, and monitoring LDAP access logs for suspicious queries targeting the vulnerable attributes. Security teams should also consider implementing attribute-level access controls and regular security assessments to identify and remediate similar access control weaknesses in directory service configurations.