CVE-2002-0334 in xtell
Summary
by MITRE
xtell (xtelld) 1.91.1 and earlier, and 2.x before 2.7, allows local users to modify files via a symlink attack on the .xtell-log file.
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Analysis
by VulDB Data Team • 10/23/2024
The vulnerability identified as CVE-2002-0334 affects xtell and xtelld services version 1.91.1 and earlier, as well as version 2.x before 2.7, creating a significant security risk through improper file handling mechanisms. This flaw enables local attackers to manipulate system files through a symbolic link attack against the .xtell-log file, representing a classic privilege escalation vector that has persisted in legacy software systems for over two decades.
The technical implementation of this vulnerability stems from inadequate file access controls and race condition exploitation opportunities within the xtell service architecture. When the service creates or updates the .xtell-log file, it fails to properly validate the file path or check for symbolic link references before performing file operations. This design flaw allows a local attacker to establish a symbolic link pointing to a target file of their choice, then trigger the service to write to what appears to be the legitimate log file but actually modifies the targeted file through the symbolic link mechanism. The vulnerability operates under CWE-377, which categorizes insecure temporary file handling, and specifically relates to CWE-59, representing improper handling of symbolic links in file operations.
The operational impact of this vulnerability extends beyond simple file modification capabilities, as it provides attackers with potential privilege escalation opportunities within the system. Local users can leverage this weakness to modify critical system files, configuration data, or sensitive information stored in locations accessible through the symbolic link attack. The attack requires local system access but does not necessitate elevated privileges, making it particularly dangerous in multi-user environments where users might have legitimate access to the service but should not be able to modify system-critical files. This vulnerability directly aligns with ATT&CK technique T1068, which covers local privilege escalation through exploitation of system vulnerabilities, and T1074, covering data staging through manipulation of system files.
Mitigation strategies for CVE-2002-0334 should focus on immediate software updates to versions 2.7 or later where the vulnerability has been addressed through proper file path validation and symbolic link checking mechanisms. Organizations should implement comprehensive patch management processes to ensure all instances of the vulnerable software are updated across their infrastructure. Additionally, system administrators should consider implementing file access controls and monitoring for unauthorized symbolic link creation in directories where critical services operate. The remediation approach should also include reviewing and hardening system configurations to prevent local users from creating symbolic links that could be exploited against vulnerable services, while maintaining proper file permissions and access controls to limit the potential impact of such attacks.