CVE-2013-1064 in apt-xapian-index
Summary
by MITRE
apt-xapian-index before 0.45ubuntu2.1, 0.44ubuntu7.1, and 0.44ubuntu5.1 does not properly use D-Bus for communication with a polkit authority, which allows local users to bypass intended access restrictions by leveraging a PolkitUnixProcess PolkitSubject race condition via a (1) setuid process or (2) pkexec process, a related issue to CVE-2013-4288.
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Analysis
by VulDB Data Team • 12/28/2024
The vulnerability described in CVE-2013-1064 affects the apt-xapian-index package version prior to specific patched releases including 0.45ubuntu2.1, 0.44ubuntu7.1, and 0.44ubuntu5.1. This issue represents a critical flaw in the privilege escalation mechanism within Ubuntu's package management system that enables local attackers to bypass intended access controls. The vulnerability stems from improper D-Bus communication patterns with the polkit authority component, creating a race condition that can be exploited by malicious local users to gain elevated privileges.
The technical flaw manifests through a specific race condition involving PolkitUnixProcess PolkitSubject handling within the D-Bus communication framework. When apt-xapian-index executes with setuid privileges or through pkexec processes, the system fails to properly validate the authentication context before granting access to restricted resources. This race condition occurs because the polkit authority does not adequately verify the process identity during the brief window between when the D-Bus message is received and when the authorization check is performed. The vulnerability specifically impacts the authentication flow where the system should verify that the requesting process has proper authorization to perform privileged operations but instead allows malicious actors to exploit timing gaps in the authorization process.
The operational impact of this vulnerability is significant as it provides local users with a means to bypass system security controls without requiring remote network access or specialized attack infrastructure. An attacker with local login access can leverage this flaw to execute privileged operations that should normally be restricted to administrators or specific system processes. The vulnerability affects the core package management functionality of Ubuntu systems and can potentially allow attackers to install malicious packages, modify system files, or escalate their privileges to root level access. This creates a substantial risk for systems where local users might have access to user accounts that are not properly secured.
This vulnerability maps to CWE-284 Access Control Issues and specifically relates to CWE-362 Race Conditions in privilege escalation scenarios. The flaw also aligns with ATT&CK technique T1068 Privilege Escalation through the exploitation of process authentication mechanisms and D-Bus communication vulnerabilities. The attack vector leverages legitimate system components while exploiting implementation weaknesses in the authorization framework, making detection more challenging. Organizations should implement immediate patching of affected systems to address this vulnerability, ensuring that all instances of apt-xapian-index are updated to versions that properly handle D-Bus communication with polkit authorities. System administrators should also review local user access controls and monitor for any suspicious privilege escalation activities that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper authentication flow implementation in setuid applications and the need for comprehensive testing of authorization mechanisms under concurrent access conditions.