CVE-2008-4645 in PhpWebGallery
Summary
by MITRE
plugins/event_tracer/event_list.php in PhpWebGallery 1.7.2 and earlier allows remote authenticated administrators to execute arbitrary PHP code via PHP sequences in the sort parameter, which is processed by create_function.
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Analysis
by VulDB Data Team • 11/08/2024
The vulnerability identified as CVE-2008-4645 affects PhpWebGallery versions 1.7.2 and earlier, specifically within the event_tracer plugin's event_list.php component. This represents a critical security flaw that enables remote authenticated administrators to execute arbitrary PHP code through manipulation of the sort parameter. The vulnerability stems from the improper handling of user-supplied input within the create_function PHP directive, which dynamically generates PHP code at runtime based on provided parameters. When an authenticated administrator accesses the event_list.php page and manipulates the sort parameter, the application processes this input without adequate sanitization or validation, allowing malicious code sequences to be executed within the web server's context.
The technical exploitation of this vulnerability occurs through the create_function PHP function which accepts user input and converts it into executable PHP code. This function is inherently dangerous when used with unsanitized input as it bypasses normal PHP parsing and execution restrictions. The sort parameter in the event_list.php file is processed by create_function, creating a code injection vector where an attacker can inject PHP code sequences that get executed by the web server. This vulnerability is classified as a code injection flaw and maps to CWE-94, which describes the weakness of allowing untrusted data to be executed as code. The attack requires only authenticated access to an administrative account, making it particularly dangerous as it leverages legitimate administrative privileges to escalate to arbitrary code execution.
The operational impact of this vulnerability is severe as it provides attackers with complete control over the web server running PhpWebGallery. Once exploited, an attacker can execute any PHP code with the privileges of the web server process, potentially leading to full system compromise. The vulnerability affects not just the gallery itself but could be used as a stepping stone for further attacks within the network infrastructure. An attacker could use this privilege to upload malicious files, establish backdoors, access sensitive data, or pivot to other systems. The attack vector is particularly concerning because it requires minimal effort beyond having administrative credentials, making it an attractive target for both insider threats and compromised administrative accounts. This vulnerability also aligns with ATT&CK technique T1059.007 which covers the use of PHP for command and control operations.
Mitigation strategies for CVE-2008-4645 focus on both immediate patching and defensive measures. The primary solution is to upgrade to PhpWebGallery version 2.0 or later where this vulnerability has been addressed through proper input sanitization and removal of the dangerous create_function usage. Organizations should implement strict input validation and sanitization for all parameters that are processed by dynamic code execution functions. Additional defensive measures include restricting administrative privileges to only necessary personnel, implementing network segmentation to limit access to administrative interfaces, and monitoring for unusual administrative activity. The vulnerability demonstrates the importance of avoiding dynamic code generation functions like create_function with unsanitized user input, aligning with security best practices outlined in OWASP Top 10 and other industry standards. Regular security audits and code reviews should specifically examine usage of dynamic code execution functions to prevent similar vulnerabilities in other applications.