CVE-2005-0448 in Perl
Summary
by MITRE
Race condition in the rmtree function in File::Path.pm in Perl before 5.8.4 allows local users to create arbitrary setuid binaries in the tree being deleted, a different vulnerability than CVE-2004-0452.
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Analysis
by VulDB Data Team • 07/01/2019
The vulnerability described in CVE-2005-0448 represents a critical race condition flaw within the File::Path Perl module that affects Perl versions prior to 5.8.4. This issue specifically targets the rmtree function which is responsible for recursively deleting directory trees. The race condition occurs during the process of directory traversal and deletion, creating a window where malicious actors can exploit the timing gap between directory checks and actual deletion operations. The vulnerability is distinct from CVE-2004-0452, indicating it addresses a separate but equally dangerous class of exploits that leverage temporal inconsistencies in file system operations.
The technical flaw manifests when the rmtree function processes directory structures containing symbolic links or when multiple processes access the same directory tree simultaneously. During the deletion process, the function performs checks to determine whether directories and files can be safely removed, but these checks occur before the actual deletion operations. This temporal gap allows a local attacker to manipulate the file system state by creating malicious setuid binaries in directories that are scheduled for deletion. The race condition typically involves a sequence where the system checks for directory permissions and existence before proceeding with deletion, but between these checks and the actual removal, an attacker can insert malicious files or modify existing ones.
The operational impact of this vulnerability is severe as it enables local privilege escalation through the creation of arbitrary setuid binaries. When a directory tree is being deleted, an attacker can place a malicious binary with setuid bits set in a location that will be processed by the rmtree function. Upon successful deletion, the malicious binary retains its setuid properties, allowing local users to execute code with elevated privileges. This vulnerability particularly affects systems where Perl scripts handle user-supplied directory paths or where automated cleanup processes utilize the affected rmtree function. The implications extend to any application or system service that relies on Perl's File::Path module for directory management operations, potentially compromising entire systems if exploited.
The vulnerability aligns with CWE-367, which addresses Time-of-Check to Time-of-Use (TOCTOU) flaws, and can be mapped to ATT&CK technique T1068, which covers Exploitation for Privilege Escalation. Organizations should immediately update to Perl version 5.8.4 or later where this race condition has been patched. Additional mitigations include implementing proper directory permission controls, avoiding the use of setuid binaries in automated deletion processes, and employing file system monitoring tools to detect unauthorized modifications during deletion operations. System administrators should also review applications that utilize the File::Path module and ensure proper input validation and sanitization to prevent exploitation through malicious directory structures or symbolic links that could trigger the race condition.