CVE-2012-1576 in atheme
Summary
by MITRE
The myuser_delete function in libathemecore/account.c in Atheme 5.x before 5.2.7, 6.x before 6.0.10, and 7.x before 7.0.0-beta2 does not properly clean up CertFP entries when a user is deleted, which allows remote attackers to access a different user account or cause a denial of service (daemon crash) via a login as a deleted user.
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Analysis
by VulDB Data Team • 12/14/2021
The vulnerability identified as CVE-2012-1576 represents a critical security flaw within the Atheme IRC services framework that affects multiple version branches including 5.x prior to 5.2.7, 6.x prior to 6.0.10, and 7.x prior to 7.0.0-beta2. This issue resides in the myuser_delete function located within the libathemecore/account.c file, which governs user account management operations within the Atheme services infrastructure. The flaw manifests when user accounts are removed from the system, specifically failing to properly handle the cleanup of CertFP (Certificate Fingerprint) entries that are associated with those accounts.
The technical implementation of this vulnerability stems from improper resource management during user account deletion processes. When a user account is deleted, the system should systematically remove all associated authentication data including CertFP entries that serve as cryptographic identifiers for user authentication. However, the myuser_delete function neglects to properly clean up these CertFP entries, leaving stale cryptographic references within the system's memory structures and database records. This incomplete cleanup creates a persistent security vector that can be exploited by malicious actors.
Remote attackers can leverage this vulnerability to achieve unauthorized access to different user accounts by exploiting the lingering CertFP entries that remain accessible after account deletion. The exploitation process typically involves attempting to log in as a deleted user account, which triggers the system to reference the stale CertFP data and potentially authenticate the attacker to another legitimate user's account. This cross-account access represents a significant compromise of user privacy and system integrity, as it allows unauthorized individuals to impersonate valid users within the IRC network.
The operational impact extends beyond unauthorized access to include potential denial of service conditions that can crash the entire daemon process. When the system attempts to process authentication requests for deleted accounts with lingering CertFP entries, the inconsistent state of the authentication data can cause memory corruption, null pointer dereferences, or other critical runtime errors that result in daemon crashes. This denial of service component makes the vulnerability particularly dangerous in environments where service availability is critical for network operations and user communication.
This vulnerability maps to CWE-200 (Information Exposure) and CWE-476 (NULL Pointer Dereference) within the Common Weakness Enumeration framework, representing information disclosure through improper cleanup of authentication data and potential system crashes due to invalid memory references. From an ATT&CK framework perspective, this vulnerability aligns with T1078 (Valid Accounts) and T1499 (Endpoint Denial of Service) techniques, enabling adversaries to maintain persistent access through compromised authentication mechanisms while simultaneously disrupting service availability.
Mitigation strategies should focus on immediate patch application to versions 5.2.7, 6.0.10, and 7.0.0-beta2 or later that contain the corrected myuser_delete function implementation. System administrators should also implement monitoring for unusual authentication patterns and account access attempts that may indicate exploitation attempts. Additionally, regular security audits of authentication systems and proper account lifecycle management procedures should be enforced to prevent similar issues in other components of the IRC services infrastructure.