CVE-2014-5459 in PHP
Summary
by MITRE
The PEAR_REST class in REST.php in PEAR in PHP through 5.6.0 allows local users to write to arbitrary files via a symlink attack on a (1) rest.cachefile or (2) rest.cacheid file in /tmp/pear/cache/, related to the retrieveCacheFirst and useLocalCache functions.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 03/29/2022
The vulnerability CVE-2014-5459 represents a critical file system permission flaw in the PHP Extension and Application Repository (PEAR) system that affects PHP versions through 5.6.0. This issue stems from improper handling of temporary cache files during package retrieval operations, creating a predictable symlink attack vector that allows local privilege escalation. The vulnerability specifically targets the PEAR_REST class within the REST.php file, which manages communication with PEAR repositories and handles local caching mechanisms. When PEAR attempts to cache package information, it creates temporary files in the /tmp/pear/cache/ directory using predictable naming conventions that include rest.cachefile and rest.cacheid. The flaw occurs because the system does not properly validate or sanitize these temporary file paths before creating symbolic links, enabling attackers to manipulate the file system through carefully crafted symlink attacks.
The technical exploitation of this vulnerability relies on the attacker's ability to create symbolic links in the temporary cache directory before PEAR performs its cache operations. When the retrieveCacheFirst and useLocalCache functions execute, they process the cache files without proper validation of the file system integrity, allowing an attacker who controls the target cache file paths to redirect file operations to arbitrary locations on the system. This creates a race condition where the attacker can establish symlinks pointing to sensitive system files or directories, such as configuration files, authentication databases, or other critical resources. The CWE-377 vulnerability classification applies here as the issue involves the use of a potentially dangerous function that creates temporary files with insecure permissions, while the CWE-22 weakness represents the improper restriction of operations within a limited scope. The vulnerability demonstrates a classic path traversal and file system manipulation attack pattern that bypasses normal access controls.
The operational impact of CVE-2014-5459 extends beyond simple local privilege escalation to potentially compromise entire system configurations and sensitive data repositories. Attackers can leverage this vulnerability to modify critical system files, inject malicious code into PEAR package installations, or gain unauthorized access to system resources that would otherwise be protected. The attack vector is particularly dangerous because it operates at the local user level, meaning that any user with access to the system can exploit this weakness to manipulate PEAR's caching mechanisms. This vulnerability affects not only individual package installations but can also compromise the integrity of the entire PEAR package management system, potentially allowing attackers to modify package metadata, inject backdoors, or redirect package downloads to malicious sources. The impact is amplified in environments where PEAR is used for automated package management or where system administrators rely on PEAR for critical infrastructure components.
Mitigation strategies for CVE-2014-5459 require immediate patching of affected PHP installations and implementation of proper file system permissions controls. The primary solution involves upgrading to PHP versions that have addressed this vulnerability through proper validation of temporary file paths and implementation of secure temporary file creation mechanisms. System administrators should also implement restrictive permissions on the /tmp/pear/cache/ directory, ensuring that only the appropriate user accounts can create or modify files within this location. The use of secure temporary file creation functions and proper file system validation should be enforced throughout the PEAR package management system. Additionally, monitoring and logging of cache file operations can help detect potential exploitation attempts, while network segmentation and privilege separation can limit the potential damage from successful attacks. The ATT&CK technique T1059.007 covers scripting languages that could be used to exploit this vulnerability, while T1548.001 addresses privilege escalation techniques that attackers might employ using such file system weaknesses. Organizations should also implement regular security audits of their PHP installations and package management systems to identify and remediate similar vulnerabilities before they can be exploited by malicious actors.