CVE-2004-0452 in Perl
Summary
by MITRE
Race condition in the rmtree function in the File::Path module in Perl 5.6.1 and 5.8.4 sets read/write permissions for the world, which allows local users to delete arbitrary files and directories, and possibly read files and directories, via a symlink attack.
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Analysis
by VulDB Data Team • 06/30/2019
The vulnerability described in CVE-2004-0452 represents a critical race condition flaw within the File::Path module of perl versions 5.6.1 and 5.8.4. This issue stems from improper handling of file permissions during directory removal operations, specifically when the rmtree function encounters symbolic links. The race condition occurs during the execution of file system operations where the timing between permission checks and actual file operations creates a window where malicious actors can exploit the system. According to CWE-367, this vulnerability falls under the category of time-of-check to time-of-use errors, where the system checks permissions at one moment but performs the actual operation at a different moment, allowing for potential manipulation.
The technical implementation of this flaw involves the rmtree function's interaction with symbolic links during directory traversal and removal processes. When perl processes a directory structure containing symbolic links, the function performs permission checks on the target directories before attempting to remove them. However, due to the race condition, an attacker can create a symbolic link that points to a target directory or file that the attacker wishes to access or delete. The window between when the system determines that a directory is accessible and when it actually attempts to remove it allows for manipulation. This creates a scenario where the system's permission checks pass successfully, but the actual removal operation targets different files than originally intended, as specified in the ATT&CK framework under technique T1059 for execution through system commands and T1070 for indicator removal.
The operational impact of this vulnerability extends beyond simple file deletion to include potential information disclosure and privilege escalation scenarios. Local users can exploit this weakness to delete arbitrary files and directories that they would normally not have permission to access, effectively bypassing standard file system permission controls. The ability to read files and directories through this mechanism provides additional attack surface for data exfiltration and reconnaissance activities. This vulnerability particularly affects systems running perl 5.6.1 or 5.8.4 where the File::Path module is utilized for directory management operations, creating a persistent threat vector for any application that relies on this module for file system cleanup operations.
Mitigation strategies for CVE-2004-0452 focus primarily on upgrading to patched versions of perl where this race condition has been resolved. System administrators should immediately update their perl installations to versions that include fixes for the File::Path module, typically perl 5.8.5 or later. Additionally, organizations should implement proper file system permission controls and avoid running applications with elevated privileges when processing directory structures that may contain symbolic links. The use of proper atomic operations and ensuring that all file system operations are completed within a single atomic transaction can help prevent similar race conditions. Network segmentation and monitoring for unusual file system activity can also help detect potential exploitation attempts. Organizations should also consider implementing proper access controls and monitoring for any unauthorized file deletion or modification operations, as outlined in the NIST Cybersecurity Framework for system protection and incident response.