CVE-2005-0073 in sympa
Summary
by MITRE
Buffer overflow in queue.c in a support script for sympa 3.3.3, when running setuid, allows local users to execute arbitrary code.
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Analysis
by VulDB Data Team • 05/30/2019
The vulnerability identified as CVE-2005-0073 represents a critical buffer overflow flaw within the sympa 3.3.3 mailing list management system. This issue specifically affects a support script named queue.c which is designed to handle queue processing operations. The vulnerability becomes particularly dangerous when the script executes with setuid privileges, creating a path for local attackers to escalate their privileges and execute arbitrary code on the affected system. The buffer overflow occurs during the processing of input data within the queue handling mechanism, where insufficient bounds checking allows attackers to overwrite adjacent memory locations.
The technical implementation of this vulnerability stems from improper input validation within the queue.c script. When the script processes queue data, it fails to adequately verify the length of input buffers before copying data into fixed-size memory locations. This classic buffer overflow condition enables attackers to overwrite return addresses, function pointers, or other critical program state information. The setuid execution context amplifies the severity because the compromised script runs with elevated privileges typically belonging to the system administrator or mail service user, providing attackers with a direct pathway to privilege escalation. This flaw directly maps to CWE-121, which categorizes stack-based buffer overflow conditions, and aligns with ATT&CK technique T1068, which covers privilege escalation through local exploits.
The operational impact of this vulnerability extends beyond simple code execution, as it fundamentally compromises the security model of the sympa mailing list system. Local users who can execute the vulnerable script gain the ability to perform actions that would normally require administrative privileges, including modifying system files, creating new user accounts, or accessing sensitive data. The attack vector is particularly concerning because it requires minimal privileges to exploit, making it accessible to any local user on the system. This vulnerability undermines the principle of least privilege and creates a persistent backdoor for attackers who may initially gain access through other means, as the compromised script can be used for long-term system compromise.
Mitigation strategies for CVE-2005-0073 must address both immediate remediation and long-term security hardening. The primary solution involves applying the vendor-provided patch or upgrade to a version of sympa that contains the necessary buffer overflow protections. Organizations should also implement immediate privilege reduction measures by ensuring that the vulnerable script does not execute with setuid permissions unless absolutely necessary for legitimate system operations. Security configurations should include regular auditing of setuid binaries and implementation of input validation controls. Additionally, system administrators should consider implementing mandatory access controls through mechanisms like SELinux or AppArmor to limit the potential impact of successful exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper input validation and privilege management in security-sensitive applications, particularly those handling user-provided data in privileged contexts.