CVE-2007-5423 in TikiWiki
Summary
by MITRE
tiki-graph_formula.php in TikiWiki 1.9.8 allows remote attackers to execute arbitrary code via PHP sequences in the f array parameter, which are processed by create_function.
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Analysis
by VulDB Data Team • 10/07/2024
The vulnerability identified as CVE-2007-5423 affects TikiWiki version 1.9.8 and represents a critical remote code execution flaw in the tiki-graph_formula.php component. This vulnerability stems from improper input validation and sanitization mechanisms that fail to properly handle user-supplied data. The flaw specifically manifests when the application processes the f array parameter through the create_function PHP function, which dynamically generates PHP code from string input. The vulnerability is classified under CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')" and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: Python" and broader code injection categories. The security implications are severe as attackers can craft malicious PHP sequences within the f parameter to execute arbitrary code on the target server with the privileges of the web application.
The technical exploitation of this vulnerability occurs through the dangerous use of PHP's create_function() function, which accepts a string containing PHP code and evaluates it at runtime. When user input is directly passed to create_function without proper sanitization or validation, attackers can inject malicious PHP code that gets executed by the server. This creates a classic code injection vector where the attacker's payload becomes part of the server-side execution environment. The vulnerability is particularly dangerous because create_function() bypasses many standard security mechanisms and can execute arbitrary PHP code with the same privileges as the web server process. The flaw demonstrates poor input handling practices and violates fundamental security principles of input validation and output encoding.
The operational impact of CVE-2007-5423 extends beyond simple code execution to encompass complete system compromise and potential data breaches. Successful exploitation allows attackers to execute commands on the vulnerable server, potentially leading to full system control, data exfiltration, and persistence mechanisms. The vulnerability affects web applications that rely on dynamic code generation and user input processing, making it particularly concerning for content management systems like TikiWiki. Attackers could leverage this vulnerability to establish backdoors, install malware, or use the compromised server as a launching point for further attacks within the network infrastructure. The vulnerability also represents a significant risk to organizations relying on TikiWiki for collaborative content management, as it could lead to unauthorized access to sensitive information and system resources.
Mitigation strategies for CVE-2007-5423 require immediate action to address the root cause of the vulnerability. The most effective approach involves upgrading to a patched version of TikiWiki that properly validates and sanitizes input parameters before processing them through dynamic code generation functions. Organizations should implement proper input validation techniques that reject or escape potentially dangerous characters and sequences in user-supplied data. The use of create_function() should be eliminated or strictly controlled in favor of safer alternatives like eval() with proper sanitization or direct function calls. Additionally, implementing web application firewalls, input filtering mechanisms, and regular security audits can help detect and prevent exploitation attempts. Security practitioners should also consider implementing principle of least privilege for web server accounts and regular monitoring for suspicious activities that might indicate exploitation attempts. This vulnerability serves as a reminder of the critical importance of secure coding practices and proper input validation in preventing remote code execution attacks.