CVE-2006-1087 in PHP-Stats
Summary
by MITRE
Direct static code injection vulnerability in the modify_config action in admin.php for PHP-Stats 0.1.9.1 and earlier allows remote authenticated administrators to execute arbitrary PHP code via the option_new[compatibility_mode] parameter, which is not filtered before being stored in config.php. NOTE: this vulnerability can be exploited by remote unauthenticated attackers in conjunction with the option[admin_pass] authentication bypass vulnerability.
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Analysis
by VulDB Data Team • 07/20/2018
The CVE-2006-1087 vulnerability represents a critical direct static code injection flaw within PHP-Stats version 0.1.9.1 and earlier, specifically affecting the modify_config action in the admin.php file. This vulnerability operates through a fundamental failure in input validation and sanitization processes, where the option_new[compatibility_mode] parameter receives no filtering before being written to the config.php configuration file. The flaw resides in the application's trust model, where authenticated administrative users can inadvertently introduce malicious code into the system configuration, creating a persistent backdoor for code execution.
The technical exploitation mechanism leverages the insecure handling of user-supplied input within the administrative interface. When an authenticated administrator modifies configuration settings through the modify_config action, the system directly incorporates the option_new[compatibility_mode] parameter into the configuration file without proper sanitization or validation. This creates a classic code injection vulnerability where malicious PHP code can be executed within the context of the web server process. The vulnerability operates at the intersection of CWE-94, which defines weaknesses in the execution of code, and CWE-20, which addresses input validation issues. The attack vector becomes particularly dangerous when combined with the authentication bypass vulnerability referenced in the CVE description, as it allows unauthenticated attackers to gain administrative privileges and subsequently exploit this code injection flaw.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise and persistent access. Once exploited, attackers can execute arbitrary PHP code with the privileges of the web server process, potentially leading to data exfiltration, system enumeration, privilege escalation, and establishment of persistent backdoors. The vulnerability's persistence stems from the fact that the malicious code is stored in the config.php file, ensuring that the malicious payload survives server restarts and system reboots. This characteristic aligns with ATT&CK technique T1059.007 for execution through PHP, and T1566 for initial access through credential compromise. The vulnerability demonstrates a failure in the principle of least privilege and proper input validation, creating a pathway for attackers to escalate their privileges from administrative access to full system compromise.
Mitigation strategies for CVE-2006-1087 require immediate attention to address both the code injection vulnerability and the authentication bypass issue. The primary remediation involves implementing proper input sanitization and validation for all user-supplied parameters before they are written to configuration files. This includes applying strict filtering to the option_new[compatibility_mode] parameter and ensuring that all configuration modifications undergo comprehensive validation before persistence. Organizations should also implement the authentication bypass vulnerability patch if it exists, as this weakness enables unauthenticated exploitation of the code injection vulnerability. The solution approach should incorporate CWE-129 and CWE-20 validation techniques to prevent malformed input from being processed. Additionally, system administrators should implement proper access controls, regular security audits, and monitoring of configuration file changes to detect potential exploitation attempts. Network segmentation and web application firewalls can provide additional defense-in-depth layers to prevent unauthorized access to administrative interfaces. The vulnerability serves as a reminder of the critical importance of input validation and the principle of least privilege in web application security, emphasizing that administrative interfaces require the most rigorous security controls.