CVE-2001-1331 in mandb
Summary
by MITRE
mandb in the man-db package before 2.3.16-3 allows local users to overwrite arbitrary files via the command line options (1) -u or (2) -c, which do not drop privileges and follow symlinks.
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Analysis
by VulDB Data Team • 07/19/2019
The vulnerability described in CVE-2001-1331 affects the mandb utility within the man-db package version 2.3.16-3 and earlier. This issue represents a privilege escalation and file overwrite vulnerability that stems from improper handling of command line arguments and privilege management within the utility. The mandb command is designed to build and update the database of manual pages, but it fails to properly drop privileges when processing certain command line options, creating a security risk for local users who can exploit this weakness.
The technical flaw occurs specifically when using the command line options -u or -c with the mandb utility. These options do not properly drop privileges after initialization, allowing a local attacker to manipulate the utility's behavior through symbolic link manipulation. The vulnerability exists because the utility follows symbolic links without adequately verifying or restricting access to the target files, enabling attackers to redirect the utility's file operations to arbitrary locations on the filesystem. This behavior creates a path traversal scenario where an attacker can cause the utility to overwrite files with malicious content or access restricted files.
From an operational impact perspective, this vulnerability enables local users to potentially overwrite critical system files, modify configuration data, or even create malicious files with elevated privileges. The attack vector is particularly concerning because it does not require any special permissions beyond local access to the system, making it exploitable by users who have minimal privileges. The vulnerability affects systems where the man-db package is installed and where users can execute the mandb utility with the affected command line options. The lack of privilege dropping means that if an attacker can control the symbolic links that mandb follows, they can effectively escalate their privileges to the level of the mandb process, which typically runs with elevated permissions.
The vulnerability aligns with CWE-276, which addresses improper privilege management, and can be mapped to ATT&CK technique T1068, which covers privilege escalation through local exploits. The attack requires a local user to have the ability to manipulate symbolic links and execute the mandb utility with the specified options. Mitigation strategies include upgrading to man-db version 2.3.16-3 or later, which addresses the privilege dropping issue, implementing proper privilege management in the utility's code, and ensuring that symbolic links are not followed in contexts where they could be manipulated by unprivileged users. Additionally, system administrators should conduct privilege audits and implement proper file system permissions to prevent unauthorized symbolic link creation and manipulation. The fix typically involves ensuring that the mandb utility properly drops privileges before processing command line arguments and implements proper validation of symbolic links to prevent unintended file operations.