CVE-2006-6550 in Phorum
Summary
by MITRE
** DISPUTED ** PHP remote file inclusion vulnerability in common.php in Phorum 3.2.11 and earlier allows remote attackers to execute arbitrary PHP code via a URL in the db_file parameter. NOTE: CVE disputes this vulnerability because db_file is defined before use.
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Analysis
by VulDB Data Team • 01/25/2025
The vulnerability described in CVE-2006-6550 relates to a potential remote file inclusion flaw in Phorum version 3.2.11 and earlier, specifically within the common.php file. This type of vulnerability falls under the category of insecure direct object references and remote code execution risks that have been historically significant in web application security. The reported issue involves the db_file parameter which, when manipulated by an attacker, could potentially allow execution of arbitrary PHP code on the target server. Such vulnerabilities represent a critical threat vector in web applications as they can enable attackers to gain unauthorized access to server resources and execute malicious code with the privileges of the web server.
From a technical perspective, the vulnerability stems from improper input validation and sanitization of user-supplied parameters. The db_file parameter in the common.php script appears to be directly incorporated into file inclusion operations without adequate sanitization or validation. This creates an opportunity for attackers to supply malicious URLs that could be interpreted as valid file paths, leading to unintended code execution. The vulnerability demonstrates poor security practices in parameter handling and file inclusion mechanisms, where user input is directly used in system calls without proper filtering or verification. This flaw aligns with CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-94 (Improper Control of Generation of Code) categories, representing both path traversal and code injection vulnerabilities.
The operational impact of this vulnerability extends beyond simple code execution, as it can potentially allow attackers to escalate privileges and gain full control over the affected web server. An attacker could leverage this vulnerability to upload malicious files, modify existing application functionality, steal sensitive data, or establish persistent access through backdoor installations. The remote nature of the attack means that exploitation does not require physical access to the system, making it particularly dangerous for web applications. This vulnerability type also relates to ATT&CK technique T1059.007 (Command and Scripting Interpreter: PowerShell) and T1105 (Remote File Copy) when attackers attempt to establish persistent access or move laterally within compromised networks. The security implications are further compounded by the fact that such vulnerabilities often remain undetected for extended periods, providing attackers with prolonged access windows.
Security mitigations for this vulnerability should focus on implementing strict input validation and sanitization mechanisms. The most effective approach involves eliminating the use of user-supplied parameters in file inclusion operations entirely, instead using whitelisting or predefined configuration options. Developers should employ proper parameter validation, input filtering, and secure coding practices to prevent such vulnerabilities from manifesting. The recommended solution includes implementing a fixed set of allowed database file paths, validating all inputs against a strict whitelist, and ensuring that no user-controllable variables are directly used in include or require statements. Additionally, organizations should conduct regular security assessments, maintain up-to-date software versions, and implement proper access controls and monitoring systems to detect and prevent exploitation attempts. The vulnerability's disputed status highlights the importance of thorough vulnerability analysis and validation processes, as some reported issues may not materialize as described in initial assessments.