CVE-2006-7090 in phpBB Security
Summary
by MITRE
PHP remote file inclusion vulnerability in phpbb_security.php in phpBB Security 1.0.1 and earlier allows remote attackers to execute arbitrary PHP code via a URL in the php_root_path parameter.
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Analysis
by VulDB Data Team • 07/13/2021
The vulnerability identified as CVE-2006-7090 represents a critical remote file inclusion flaw within the phpBB Security extension version 1.0.1 and earlier. This security weakness resides in the phpbb_security.php file and specifically targets the php_root_path parameter which is susceptible to manipulation by remote attackers. The vulnerability falls under the category of insecure direct object references and represents a classic example of how improper input validation can lead to arbitrary code execution. According to CWE-98, this vulnerability is classified as improper input validation leading to inclusion of arbitrary files, while the ATT&CK framework would categorize this under T1190 for exploitation of remote services and T1059 for execution of malicious code through command injection mechanisms.
The technical implementation of this vulnerability occurs when the phpBB Security extension fails to properly validate or sanitize the php_root_path parameter before using it in file inclusion operations. Attackers can craft malicious URLs and pass them as values to this parameter, causing the application to include and execute arbitrary PHP code from remote servers. This flaw essentially allows an attacker to bypass normal access controls and inject malicious code directly into the web application's execution environment. The vulnerability's impact is amplified by the fact that it affects a widely used bulletin board system where phpBB Security extension is commonly deployed, making it an attractive target for automated exploitation tools and malicious actors seeking to compromise web servers.
The operational implications of this vulnerability extend far beyond simple code execution, as it provides attackers with a foothold for further system compromise and data exfiltration. Once an attacker successfully exploits this vulnerability, they can execute arbitrary commands on the affected server, potentially gaining full control over the web application and underlying system. This can lead to unauthorized access to sensitive user data, server-side code manipulation, and establishment of persistent backdoors. The vulnerability also demonstrates poor security practices in input handling and file inclusion mechanisms, which are fundamental requirements for secure application development. Organizations running vulnerable versions of phpBB Security are at significant risk of being compromised, especially when the affected systems are publicly accessible and lack proper network segmentation or intrusion detection measures.
Mitigation strategies for CVE-2006-7090 require immediate action to address the root cause of the vulnerability through proper input validation and sanitization. The most effective immediate solution involves upgrading to phpBB Security version 1.0.2 or later, where the vulnerability has been patched and proper parameter validation has been implemented. System administrators should also implement proper input filtering and validation mechanisms that reject or sanitize any URL parameters before they are processed by the application. Network-level protections such as web application firewalls and intrusion prevention systems can provide additional layers of defense against exploitation attempts. Security monitoring should include detection of suspicious file inclusion patterns and unusual parameter values that may indicate exploitation attempts. The vulnerability also highlights the importance of following secure coding practices and conducting regular security assessments to identify and remediate similar flaws in application code. Organizations should also consider implementing principle of least privilege for web application directories and files to limit the potential damage from successful exploitation attempts.