CVE-2008-2827 in Perl
Summary
by MITRE
The rmtree function in lib/File/Path.pm in Perl 5.10 does not properly check permissions before performing a chmod, which allows local users to modify the permissions of arbitrary files via a symlink attack, a different vulnerability than CVE-2005-0448 and CVE-2004-0452.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/26/2024
The vulnerability described in CVE-2008-2827 resides within the rmtree function of Perl's File::Path module, specifically affecting Perl version 5.10. This flaw represents a classic symlink attack vector that exploits improper permission handling during file system operations. The vulnerability stems from the function's failure to adequately validate file permissions before executing chmod operations, creating a window where malicious actors can manipulate file permissions through symbolic link manipulation.
The technical implementation of this vulnerability involves the rmtree function's interaction with symbolic links in a manner that bypasses normal permission checks. When the function encounters a symbolic link during directory traversal, it does not properly verify whether the target of the link is accessible or if the link itself represents a security risk. This oversight allows attackers to create malicious symbolic links that point to sensitive files or directories, enabling them to modify permissions of files they would normally not have access to. The flaw operates at the filesystem level where the function's permission checking mechanism is bypassed during the chmod operation, creating a privilege escalation path.
From an operational perspective, this vulnerability presents significant risks to system security as it allows local users to potentially gain unauthorized access to sensitive files or directories. The impact extends beyond simple permission modification, as attackers can use this technique to escalate privileges, hide malicious files, or create persistent access points within the system. The vulnerability is particularly concerning because it operates silently without generating obvious error messages, making detection difficult during routine system monitoring. Attackers can leverage this flaw to compromise system integrity by modifying permissions of critical system files, configuration files, or user data files.
The security implications of this vulnerability align with CWE-367, which addresses Time-of-Check to Time-of-Use (TOCTOU) flaws in file system operations. This classification indicates that the vulnerability represents a race condition where the system checks file permissions at one point and then performs operations at a later point, allowing attackers to manipulate the system state between these checks. The flaw also relates to ATT&CK technique T1068, which covers 'Local Privilege Escalation' through exploitation of system vulnerabilities. Organizations running affected Perl versions should prioritize patching or implementing immediate mitigations, as this vulnerability can be exploited by any local user with minimal technical expertise, making it a significant risk to system security.
Mitigation strategies for CVE-2008-2827 include upgrading to a patched version of Perl that addresses the rmtree function's permission checking mechanism. System administrators should also implement monitoring for suspicious symbolic link creation patterns and ensure proper file system permissions are maintained. Additionally, restricting local user privileges where possible and implementing proper file system auditing can help detect exploitation attempts. The vulnerability demonstrates the critical importance of proper permission validation in system libraries, as even seemingly benign functions can represent security risks when they fail to properly validate system state during operation.