CVE-2007-4636 in phpBG
Summary
by MITRE
Multiple PHP remote file inclusion vulnerabilities in phpBG 0.9.1 allow remote attackers to execute arbitrary PHP code via a URL in the rootdir parameter to (1) intern/admin/other/backup.php, (2) intern/admin/, (3) intern/clan/member_add.php, (4) intern/config/key_2.php, or (5) intern/config/forum.php.
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Analysis
by VulDB Data Team • 10/02/2024
The vulnerability identified as CVE-2007-4636 represents a critical remote file inclusion flaw affecting phpBG version 0.9.1, a content management system that was widely used for managing clan websites and gaming communities during the mid-2000s. This vulnerability stems from improper input validation within several administrative and configuration scripts, creating a pathway for malicious actors to inject and execute arbitrary PHP code on vulnerable systems. The flaw specifically manifests in five distinct script files including backup.php, member_add.php, and various configuration files, all of which accept user-controllable input through the rootdir parameter without adequate sanitization or validation mechanisms.
The technical exploitation of this vulnerability follows the classic remote file inclusion pattern where an attacker can manipulate the rootdir parameter to point to a malicious remote URL containing crafted PHP code. When the vulnerable application processes this parameter, it includes the remote file using PHP's include or require functions, effectively executing the attacker-controlled code within the context of the web server. This vulnerability directly maps to CWE-88, which describes improper neutralization of special elements used in an expression, specifically the lack of proper input validation for file inclusion parameters. The attack vector aligns with ATT&CK technique T1190, which covers exploiting vulnerabilities in remote services, and T1059, covering command and scripting interpreter execution through remote code injection.
The operational impact of this vulnerability is severe and multifaceted, as successful exploitation can result in complete system compromise, data exfiltration, and potential lateral movement within affected networks. Attackers can leverage this vulnerability to establish persistent backdoors, install additional malware, or use the compromised system as a launch point for further attacks against other network resources. The vulnerability affects the core functionality of phpBG's administrative interface, potentially allowing unauthorized users to gain elevated privileges and modify critical system files. Organizations running these vulnerable applications face significant risk of data breaches, service disruption, and potential regulatory compliance violations, particularly in environments where sensitive clan member data, forum content, or administrative configurations are stored.
Mitigation strategies for CVE-2007-4636 require immediate remediation actions including applying the vendor-supplied patches or upgrading to patched versions of phpBG, as the vulnerability has been addressed in subsequent releases. System administrators should implement input validation measures such as using allowlists for parameter values, implementing proper URL validation, and disabling remote file inclusion features in PHP configurations. Network-level protections including firewall rules to restrict access to administrative interfaces and web application firewalls can provide additional defense in depth. The vulnerability also highlights the importance of secure coding practices, particularly the principle of least privilege, where applications should never include files based on user-controllable input without extensive validation. Organizations should conduct comprehensive vulnerability assessments of their web applications to identify similar issues and implement proper input sanitization mechanisms to prevent similar remote file inclusion attacks in the future.