CVE-1999-0718 in GINA
Summary
by MITRE
IBM GINA, when used for OS/2 domain authentication of Windows NT users, allows local users to gain administrator privileges by changing the GroupMapping registry key.
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Analysis
by VulDB Data Team • 01/24/2025
The vulnerability described in CVE-1999-0718 represents a critical privilege escalation flaw within IBM's Generic Identification and Authentication (GINA) module, specifically when configured for OS/2 domain authentication of Windows NT users. This issue arises from the improper handling of registry key modifications that control group mappings between different operating systems within a heterogeneous network environment. The GINA component serves as the authentication interface for Windows NT systems and when integrated with IBM OS/2 domain authentication services, creates a complex authentication pathway that inadvertently exposes a security weakness through registry manipulation.
The technical flaw manifests through the GroupMapping registry key, which controls how user groups from the OS/2 domain are translated and mapped to Windows NT user privileges. Local users with access to the system can modify this registry key to alter the group membership mappings, effectively granting themselves administrative rights within the Windows NT environment. This occurs because the GINA module does not properly validate or sanitize registry modifications made to the GroupMapping key, allowing unauthorized changes that bypass normal authentication and authorization controls. The vulnerability specifically leverages the trust relationship between different operating systems and exploits the lack of proper access controls on critical registry entries that govern user privilege assignment.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it fundamentally undermines the security model of the Windows NT system when integrated with IBM OS/2 authentication services. Local attackers can exploit this weakness to gain full administrative control without requiring legitimate credentials or authentication factors, making it particularly dangerous in environments where multiple operating systems coexist. The vulnerability affects systems where IBM GINA is configured for cross-platform authentication, creating a persistent backdoor that remains active until the registry key is properly secured or the authentication module is updated. This weakness can be exploited repeatedly and often goes undetected since the changes occur at the registry level rather than through obvious authentication failures or network-based attacks.
Mitigation strategies for this vulnerability require immediate registry key protection measures, including implementing proper access control lists on the GroupMapping registry key to restrict modifications to authorized administrators only. System administrators should also consider disabling the IBM GINA module for OS/2 domain authentication when it is not strictly required, or implementing additional authentication layers that do not rely on potentially vulnerable registry configurations. The vulnerability aligns with CWE-276, which addresses improper privilege management and inadequate access control, and can be mapped to ATT&CK technique T1068, which covers privilege escalation through local exploitation of system vulnerabilities. Organizations should also implement regular security auditing procedures to monitor for unauthorized registry modifications and establish proper change management protocols for critical system configuration elements. Additionally, this vulnerability highlights the importance of secure configuration management and the potential risks associated with cross-platform authentication integration that may introduce unexpected security weaknesses into otherwise secure systems.