CVE-2005-3903 in UnixWare
Summary
by MITRE
Buffer overflow in uidadmin in SCO Unixware 7.1.3 and 7.1.4 allows local users to execute arbitrary code via a -S (scheme) argument that specifies a large file, a different vulnerability than CVE-2001-1063.
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Analysis
by VulDB Data Team • 06/06/2019
The vulnerability identified as CVE-2005-3903 represents a critical buffer overflow flaw within the uidadmin utility of SCO Unixware operating systems version 7.1.3 and 7.1.4. This issue specifically manifests when the utility processes a -S (scheme) argument that references a large file, creating an exploitable condition that enables local attackers to gain elevated privileges and execute arbitrary code on the affected system. The vulnerability operates through a classic buffer overflow mechanism where insufficient input validation allows an attacker to write beyond the allocated memory boundaries of the scheme parameter buffer.
The technical implementation of this vulnerability stems from improper bounds checking within the uidadmin utility's handling of command-line arguments. When a malicious user provides a scheme file that exceeds the predetermined buffer size, the excess data overflows into adjacent memory regions, potentially corrupting critical program state information and allowing for code execution control. This flaw falls under the CWE-121 buffer overflow category, specifically classified as a stack-based buffer overflow that occurs during argument parsing operations. The vulnerability is particularly concerning because it requires only local user access to exploit, making it a privilege escalation vector that can be leveraged by users with minimal system privileges to achieve root access.
From an operational impact perspective, this vulnerability poses significant security risks to SCO Unixware systems deployed in enterprise environments where local user access might be more prevalent than anticipated. The ability to execute arbitrary code with elevated privileges essentially provides attackers with complete system compromise capabilities, enabling them to install backdoors, modify system files, access sensitive data, or establish persistent access. The vulnerability operates at the local privilege escalation level, which aligns with ATT&CK technique T1068 (Local Privilege Escalation) and T1548.001 (Abuse Elevation Control Mechanism). Organizations running these older SCO Unixware versions face substantial risk of unauthorized system compromise, particularly in environments where security controls are not properly enforced and where users might have legitimate access to the system.
Mitigation strategies for CVE-2005-3903 should prioritize immediate system updates and patches provided by SCO, as this vulnerability was addressed through official security releases for the affected Unixware versions. System administrators should implement strict access controls to limit local user privileges and monitor for suspicious uidadmin usage patterns. Additionally, security monitoring should focus on detecting unusual file access patterns related to scheme files and command-line argument usage. The implementation of address space layout randomization and stack canaries could provide additional defense-in-depth measures, though these protections may not be available in the older Unixware versions. Organizations should also consider implementing network segmentation and access control measures to limit the potential impact of local privilege escalation attacks, while maintaining regular security assessments to identify and remediate similar vulnerabilities across their Unixware infrastructure.