CVE-2006-4204 in PHProjekt
Summary
by MITRE
Multiple PHP remote file inclusion vulnerabilities in PHProjekt 5.1 and possibly earlier allow remote attackers to execute arbitrary PHP code via a URL in the (1) path_pre parameter in lib/specialdays.php and the (2) lib_path parameter in lib/dbman_filter.inc.php.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/14/2024
The vulnerability identified as CVE-2006-4204 represents a critical remote code execution flaw affecting PHProjekt version 5.1 and potentially earlier releases. This security weakness stems from improper input validation within the application's file inclusion mechanisms, creating an exploitable condition that allows remote attackers to inject malicious PHP code through carefully crafted URLs. The vulnerability manifests in two distinct locations within the application's codebase, specifically targeting parameter handling in different library files. The first vulnerable parameter path_pre in lib/specialdays.php accepts user-supplied URLs that are directly incorporated into file inclusion operations without adequate sanitization. Similarly, the lib_path parameter in lib/dbman_filter.inc.php presents an identical risk by accepting external URL references that bypass proper validation checks. Both instances demonstrate a classic remote file inclusion vulnerability pattern that aligns with CWE-88, which describes improper neutralization of special elements used in an expression. The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise, as attackers can leverage these entry points to deploy backdoors, exfiltrate sensitive data, or establish persistent access to affected systems. According to ATT&CK framework, this vulnerability maps to T1190 - Exploit Public-Facing Application, where adversaries exploit weaknesses in web applications to gain unauthorized access. The remote nature of this vulnerability means that attackers do not require physical access to the target system, making it particularly dangerous for publicly accessible web applications. Organizations running affected versions of PHProjekt face significant risk exposure, as the vulnerability can be exploited through simple HTTP requests containing malicious URLs in the targeted parameters. The flaw fundamentally undermines the application's security model by allowing arbitrary code execution, which violates fundamental principles of secure coding practices. This vulnerability also highlights the importance of input validation and proper parameter handling in web applications, as the issue could have been prevented through robust sanitization of user inputs before they are processed in file inclusion contexts. The widespread use of PHProjekt in enterprise environments increases the potential impact of this vulnerability, as successful exploitation can lead to complete system compromise and data breaches. Security professionals should note that this vulnerability represents an early example of how improper parameter handling in PHP applications can create severe security consequences, emphasizing the need for comprehensive security testing and input validation in all web application development processes.
The technical implementation of this vulnerability relies on the PHP include or require functions being called with user-controllable parameters. When attackers supply malicious URLs through the vulnerable parameters, the PHP interpreter processes these inputs as if they were legitimate file paths, effectively executing any PHP code contained within the remote files. This behavior directly relates to CWE-94, which describes the execution of arbitrary code due to improper handling of dynamic code generation. The vulnerability's exploitation requires minimal technical expertise, making it particularly dangerous for unpatched systems. Attackers can leverage this flaw to execute commands on the target server with the privileges of the web application user, potentially leading to full system compromise. The affected parameters path_pre and lib_path represent common patterns in web applications where configuration paths are dynamically set based on user input, but without proper validation mechanisms. This vulnerability demonstrates the critical importance of the principle of least privilege, as successful exploitation can grant attackers elevated privileges within the application environment. The vulnerability also highlights the need for proper error handling and input validation, as the lack of these security measures in the affected application versions creates exploitable conditions that attackers can readily identify and exploit. From a security perspective, this vulnerability underscores the necessity of implementing proper secure coding practices, including parameter validation, input sanitization, and the principle of least privilege in all web application development efforts. The exploitation of this vulnerability can lead to various secondary effects including data exfiltration, system reconnaissance, and establishment of persistent access points within the compromised environment.
Mitigation strategies for CVE-2006-4204 must address both immediate remediation and long-term security improvements. The most effective immediate solution involves applying the vendor-supplied patches or upgrading to versions of PHProjekt that have addressed this vulnerability. Organizations should implement proper input validation mechanisms to ensure that all user-supplied parameters are properly sanitized before being used in file inclusion operations. The implementation of allow_url_include and allow_url_fopen directives in PHP configuration should be carefully reviewed, as these settings can either enable or disable remote file inclusion functionality. Security measures should include the deployment of web application firewalls that can detect and block malicious requests attempting to exploit this vulnerability. Network segmentation and access control measures can help limit the potential impact of successful exploitation attempts. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other applications. The vulnerability also emphasizes the importance of maintaining up-to-date software versions and implementing proper security monitoring to detect unauthorized access attempts. Organizations should establish comprehensive incident response procedures to address successful exploitation attempts. The remediation process should include thorough code review to identify similar patterns in other parts of the application that might present equivalent vulnerabilities. Additionally, security awareness training for developers should emphasize secure coding practices, particularly around parameter handling and file inclusion operations. Implementation of automated security scanning tools can help identify similar vulnerabilities in the codebase. The vulnerability serves as a reminder of the critical importance of regular security updates and proper configuration management in maintaining secure web applications. Organizations should also consider implementing application-level controls such as input validation libraries and secure coding frameworks to prevent similar issues in future development cycles.