CVE-2008-7064 in Quicksilver Forums
Summary
by MITRE
Directory traversal vulnerability in the get_lang function in global.php in Quicksilver Forums 1.4.2 and earlier, as used in QSF Portal before 1.4.5, when running on Windows, allows remote attackers to include and execute arbitrary local files via a "\" (backslash) in the lang parameter to index.php, which bypasses a protection mechanism that only checks for "/" (forward slash), as demonstrated by uploading and including PHP code in an avatar file.
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Analysis
by VulDB Data Team • 11/11/2024
The vulnerability identified as CVE-2008-7064 represents a critical directory traversal flaw in Quicksilver Forums version 1.4.2 and earlier, specifically affecting the global.php file's get_lang function. This security weakness exists within the QSF Portal software ecosystem before version 1.4.5 and demonstrates a significant oversight in input validation mechanisms that affects Windows-based deployments. The flaw exploits a fundamental protection mechanism that only scrutinizes forward slashes in file path parameters while completely overlooking backslash characters, creating a bypass opportunity for malicious actors seeking unauthorized file access.
The technical implementation of this vulnerability stems from inadequate input sanitization within the get_lang function which processes language parameter values through the index.php script. When a remote attacker submits a malicious lang parameter containing backslash characters, the system fails to properly validate or sanitize this input before using it in file inclusion operations. The protection mechanism designed to prevent directory traversal attacks only examines forward slash characters in the input stream, leaving backslashes unfiltered and allowing them to pass through the validation layer. This design flaw enables attackers to manipulate file paths and access arbitrary local files on the server.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to execute arbitrary code on the affected system. The demonstration of this vulnerability involves uploading PHP code within avatar files and subsequently leveraging the directory traversal mechanism to include and execute this malicious code. This exploitation pathway creates a persistent threat vector that allows attackers to gain unauthorized access to the server environment, potentially leading to complete system compromise, data exfiltration, and further lateral movement within network infrastructure. The vulnerability affects Windows-based deployments specifically, indicating platform-specific implementation issues that may not manifest in other operating system environments.
The security implications of CVE-2008-7064 align with CWE-22, which categorizes directory traversal vulnerabilities as a common weakness in software design that allows attackers to access files outside of intended directories. This vulnerability also maps to ATT&CK technique T1566.001, representing the exploitation of vulnerabilities in remote services for initial access, and T1059.007, which covers the execution of code through web shells or similar mechanisms. Organizations running affected versions of Quicksilver Forums face significant risk of unauthorized access and potential system compromise, particularly in environments where the software operates with elevated privileges or contains sensitive user data. The vulnerability represents a classic example of how insufficient input validation can create severe security implications in web applications.
Mitigation strategies for this vulnerability require immediate patching to version 1.4.5 or later of the QSF Portal software, which addresses the flawed input validation mechanism. System administrators should implement comprehensive input filtering that validates all potential path traversal characters including both forward slashes and backslashes, ensuring that all user-supplied input undergoes thorough sanitization before being processed by file inclusion functions. Additional protective measures include implementing proper file access controls, restricting web server permissions to prevent unauthorized file uploads, and establishing monitoring mechanisms to detect suspicious file inclusion patterns. Organizations should also consider implementing web application firewalls that can detect and block malicious path traversal attempts, while conducting regular security audits to identify similar validation weaknesses in other applications. The remediation process must include thorough testing to ensure that the patched version functions correctly while maintaining security posture against similar vulnerabilities.