CVE-2007-6624 in PNphpBB
Summary
by MITRE
Directory traversal vulnerability in printview.php in PNphpBB2 1.2i and earlier allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the phpEx parameter.
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Analysis
by VulDB Data Team • 10/13/2024
The CVE-2007-6624 vulnerability represents a critical directory traversal flaw within the PNphpBB2 1.2i software suite that exposes remote attackers to arbitrary code execution capabilities. This vulnerability specifically targets the printview.php script which fails to properly validate user input parameters, creating an exploitable condition that allows malicious actors to navigate the file system beyond intended boundaries. The flaw resides in the phpEx parameter handling where the application does not adequately sanitize or filter input containing directory traversal sequences such as .. (dot dot) characters. This weakness enables attackers to manipulate file inclusion mechanisms and potentially access sensitive system files or execute malicious code with the privileges of the web server process.
The technical implementation of this vulnerability aligns with CWE-22, which classifies directory traversal or path traversal attacks as a common weakness in software applications. Attackers can exploit this flaw by crafting malicious URLs that include double dot sequences in the phpEx parameter, allowing them to traverse directories and include local files that should remain protected from external access. The vulnerability operates at the application layer and can be classified under the ATT&CK technique T1059.007 for command and scripting interpreter, specifically focusing on PHP script injection. When exploited, the vulnerability can lead to complete system compromise as attackers gain access to database credentials, configuration files, and potentially escalate privileges to execute arbitrary commands on the affected server.
The operational impact of CVE-2007-6624 extends beyond simple information disclosure to encompass full system compromise and persistent access capabilities. Remote attackers can leverage this vulnerability to include and execute local files such as system configuration files, database connection details, or even malicious PHP shells that provide backdoor access. The vulnerability affects not just individual user sessions but can potentially compromise the entire web application infrastructure, making it particularly dangerous for organizations that rely on vulnerable phpBB installations. The exploitation requires minimal prerequisites beyond basic web access and understanding of the application's file structure, making it a highly attractive target for automated attack tools and less sophisticated threat actors.
Organizations should implement immediate mitigations including input validation and sanitization of all user-supplied parameters, particularly those used in file inclusion operations. The most effective defense involves implementing proper parameter validation that rejects or filters out directory traversal sequences such as .. or %2e%2e. Additionally, applications should employ secure coding practices that utilize whitelisting approaches for file operations and avoid dynamic file inclusion based on user input. System administrators should also consider implementing web application firewalls that can detect and block suspicious directory traversal patterns, and regularly update vulnerable applications to patched versions. The vulnerability demonstrates the importance of secure input handling and proper file access controls, emphasizing that applications must never trust user input and must always validate and sanitize all external data before processing. Organizations should also conduct comprehensive security assessments to identify similar vulnerabilities in other applications and implement proper security monitoring to detect exploitation attempts.