CVE-2003-0607 in xconq
Summary
by MITRE
Buffer overflow in xconq 7.4.1 allows local users to become part of the "games" group via the (1) USER or (2) DISPLAY environment variables.
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Analysis
by VulDB Data Team • 04/22/2019
The vulnerability described in CVE-2003-0607 represents a classic buffer overflow flaw within the xconq 7.4.1 software implementation that enables local privilege escalation through improper environment variable handling. This issue specifically affects the xconq application which is a multiplayer strategy game that requires proper group membership for certain operational functions. The vulnerability manifests when the application processes the USER or DISPLAY environment variables without adequate bounds checking, creating an exploitable condition that can be leveraged by local attackers to gain elevated privileges.
The technical implementation of this vulnerability stems from inadequate input validation within the xconq application's environment variable processing code. When the application encounters the USER or DISPLAY environment variables, it fails to properly validate the length of these inputs before copying them into fixed-size buffers. This classic buffer overflow condition occurs because the application uses unsafe string handling functions that do not perform bounds checking, allowing attackers to overwrite adjacent memory locations. The specific nature of the overflow enables attackers to manipulate the program's execution flow and potentially inject malicious code or alter program state. According to CWE standards, this corresponds to CWE-121, which describes stack-based buffer overflow conditions that occur when insufficient space is allocated for data or when bounds checking is omitted during string operations.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it allows local users to effectively become members of the "games" group without proper authorization. This group membership provides access to resources and capabilities that would normally be restricted, potentially enabling attackers to execute privileged operations or access restricted files and system resources. The exploitation process requires local system access but does not necessitate network connectivity, making it particularly dangerous in multi-user environments where attackers might already have legitimate access to system resources. The vulnerability affects systems where xconq is installed with setuid or setgid permissions, as these applications can be leveraged to elevate privileges from regular user accounts to group-level permissions.
The attack vector for this vulnerability is straightforward and relies on local system compromise, as attackers need to control the environment variables before launching the vulnerable application. This typically involves crafting malicious USER or DISPLAY environment variable values that exceed the buffer capacity, causing the overflow to overwrite the group membership information or execution context. The exploitation process aligns with ATT&CK techniques under T1068, which describes privilege escalation through the exploitation of system vulnerabilities, and T1059, which covers the execution of commands through environment variable manipulation. Security professionals should note that this vulnerability represents a significant risk in environments where xconq is installed with elevated permissions or where multiple users share the same system resources.
Mitigation strategies for this vulnerability should focus on immediate patching of the xconq application to version 7.4.2 or later, which contains the necessary buffer overflow protections and bounds checking mechanisms. System administrators should also implement proper environment variable validation and sanitization procedures, ensuring that all input parameters are strictly validated before being processed by vulnerable applications. Additional protective measures include reviewing and restricting setuid/setgid permissions on the xconq binary, implementing mandatory access controls, and monitoring for unauthorized environment variable modifications. The vulnerability demonstrates the critical importance of input validation and proper buffer management in preventing privilege escalation attacks, and serves as a reminder of the necessity for regular security updates and comprehensive code review practices. Organizations should also consider implementing runtime protection mechanisms that can detect and prevent buffer overflow exploitation attempts, particularly in legacy systems where patching may not be immediately feasible.