CVE-2006-5610 in Fully Modded phpBB
Summary
by MITRE
PHP remote file inclusion vulnerability in player/includes/common.php in Teake Nutma Foing, as modified in Fully Modded phpBB (phpbbfm) 2021.4.40, allows remote attackers to execute arbitrary PHP code via a URL in the phpbb_root_path parameter.
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Analysis
by VulDB Data Team • 04/25/2026
The vulnerability identified as CVE-2006-5610 represents a critical remote file inclusion flaw in the Teake Nutma Foing application, specifically within the player/includes/common.php component. This issue was exacerbated when the application was modified in the Fully Modded phpBB (phpbbfm) version 2021.4.40, creating a dangerous attack vector that enables remote code execution. The vulnerability stems from improper input validation and sanitization of the phpbb_root_path parameter, which is processed without adequate security measures to prevent malicious input from being interpreted as legitimate file paths. This weakness allows attackers to inject arbitrary URLs that are then included and executed as PHP code on the target server.
The technical exploitation of this vulnerability occurs through manipulation of the phpbb_root_path parameter, which is typically used to define the root directory path for phpBB installations. When an attacker supplies a malicious URL as the value for this parameter, the application fails to validate or sanitize the input before using it in include or require statements. This creates an opportunity for attackers to reference external malicious files hosted on remote servers, effectively allowing them to execute arbitrary PHP code with the privileges of the web server process. The vulnerability is classified as a remote file inclusion (RFI) attack, which falls under CWE-88, specifically related to improper neutralization of special elements used in an expression. The attack chain typically involves crafting a malicious URL that points to attacker-controlled PHP code, which gets executed when the vulnerable application processes the parameter.
The operational impact of this vulnerability is severe and multifaceted, affecting system confidentiality, integrity, and availability. Successful exploitation allows attackers to gain complete control over the affected web server, enabling them to execute commands, access sensitive data, install backdoors, or establish persistent access to the compromised system. The vulnerability affects not only the targeted application but potentially the entire underlying server infrastructure, as the code execution occurs with the privileges of the web server process. This can lead to data breaches, system compromise, and unauthorized access to databases or other server resources. The vulnerability also aligns with ATT&CK technique T1190, which describes the use of remote file inclusion to execute arbitrary code, and T1059, which covers the execution of commands through various scripting languages including PHP. Organizations running affected versions of the application face significant risk of unauthorized access and potential data loss, particularly in environments where the application handles sensitive user information or business-critical data.
Mitigation strategies for this vulnerability require immediate action to address the root cause through proper input validation and sanitization. The primary recommendation involves implementing strict parameter validation that rejects any input containing URLs or external references, ensuring that only local file paths are accepted for the phpbb_root_path parameter. Organizations should also implement proper input sanitization techniques that remove or encode special characters that could be used in malicious injection attempts. Additionally, the application should be updated to a patched version that addresses the vulnerability, as the original version has been superseded by security fixes. Network-level defenses such as web application firewalls can provide additional protection by filtering malicious requests before they reach the vulnerable application. The implementation of secure coding practices, including the use of allowlists for valid input parameters and the enforcement of the principle of least privilege, can significantly reduce the risk of exploitation. Organizations should also conduct regular security assessments and vulnerability scanning to identify similar weaknesses in other applications and ensure that proper security measures are in place to prevent unauthorized code execution through parameter manipulation.