CVE-2011-4459 in Best Practical
Summary
by MITRE
Best Practical Solutions RT 3.x before 3.8.12 and 4.x before 4.0.6 does not properly disable groups, which allows remote authenticated users to bypass intended access restrictions in opportunistic circumstances by leveraging a group membership.
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Analysis
by VulDB Data Team • 12/03/2021
The vulnerability identified as CVE-2011-4459 affects Best Practical Solutions RT versions prior to 3.8.12 for the 3.x series and 4.0.6 for the 4.x series. This security flaw represents a critical access control weakness that undermines the intended security model of the ticketing system. The vulnerability stems from improper group disablement mechanisms within the application's permission architecture, creating a scenario where authenticated users can exploit group membership relationships to gain unauthorized access to restricted resources. The issue manifests when the system fails to properly enforce group membership restrictions, allowing users to bypass access controls through opportunistic exploitation.
The technical implementation of this vulnerability resides in the application's group management and access control subsystem. When groups are disabled within RT, the system should ensure that no members of those groups can access resources that are restricted to specific group memberships. However, the flaw allows authenticated users to leverage their group membership status even when those groups have been administratively disabled. This occurs because the access control checks do not properly validate whether a user's group memberships are still active or have been explicitly disabled. The vulnerability is particularly concerning because it operates at the authentication and authorization layers, where proper access controls are fundamental to system security. According to CWE standards, this vulnerability maps to CWE-284 which describes improper access control, specifically focusing on insufficient group membership validation and access restriction enforcement.
The operational impact of this vulnerability extends beyond simple unauthorized access to potentially compromise the integrity of the entire ticketing system. Attackers can exploit this weakness to access sensitive tickets, view confidential information, modify records, or perform administrative actions that should be restricted to authorized personnel only. The opportunistic nature of the vulnerability means that the attack vector becomes more prevalent when users have legitimate group memberships that are later disabled but not properly revoked from active sessions. This creates a window of opportunity where users can continue to operate with elevated privileges even after their group memberships have been administratively removed. The attack surface is particularly broad as RT systems often contain sensitive business data, user information, and system configuration details that require strict access controls.
Mitigation strategies for CVE-2011-4459 should prioritize immediate patching of affected RT versions to the recommended secure releases. Organizations must ensure that all instances of RT are updated to versions 3.8.12 or later for the 3.x series and 4.0.6 or later for the 4.x series. Beyond patching, administrators should implement comprehensive access control reviews to validate that group memberships are properly synchronized with user access requirements. The system should be configured to enforce immediate invalidation of group memberships when groups are disabled, ensuring that no stale permissions persist in active sessions. Network segmentation and monitoring should be implemented to detect unusual access patterns that might indicate exploitation attempts. According to ATT&CK framework, this vulnerability aligns with T1078 which covers valid accounts and privilege escalation techniques, particularly focusing on the abuse of group membership for unauthorized access. Organizations should also conduct regular security audits of their RT configurations and implement proper change management processes to ensure that access control modifications are properly enforced and monitored.