CVE-2007-3096 in PBLang
Summary
by MITRE
Directory traversal vulnerability in login.php in PBLang (PBL) 4.67.16.a and earlier, when magic_quotes_gpc is disabled, allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the lang parameter.
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Analysis
by VulDB Data Team • 09/20/2024
The vulnerability identified as CVE-2007-3096 represents a critical directory traversal flaw within the PBLang content management system version 4.67.16.a and earlier releases. This security weakness specifically affects the login.php script and manifests when the PHP configuration parameter magic_quotes_gpc is disabled. The vulnerability stems from insufficient input validation and sanitization of user-supplied data, particularly the lang parameter that controls language selection within the application's authentication interface. Attackers can exploit this flaw by manipulating the lang parameter to include directory traversal sequences such as .. which allows them to navigate outside the intended directory structure and access arbitrary local files on the server.
The technical exploitation of this vulnerability occurs through the manipulation of the lang parameter in the login.php script. When magic_quotes_gpc is disabled, the application fails to properly sanitize user input before using it in file inclusion operations. This creates an opportunity for attackers to construct malicious file paths that traverse the directory structure and gain access to sensitive files that should remain protected. The vulnerability essentially allows attackers to bypass normal file access controls and potentially execute arbitrary code on the target system. This type of flaw falls under the Common Weakness Enumeration category CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can lead to complete system compromise when combined with other attack vectors. An attacker who successfully exploits this vulnerability can potentially read sensitive system files, configuration data, database credentials, and other confidential information stored on the server. In many cases, this initial access can serve as a foothold for further exploitation, allowing attackers to escalate privileges, establish persistent backdoors, or launch additional attacks against the internal network. The vulnerability is particularly dangerous in environments where the web application runs with elevated privileges or where sensitive data is stored in accessible locations.
Mitigation strategies for CVE-2007-3096 should focus on both immediate patching and defensive measures. The most effective solution involves upgrading to a patched version of PBLang that properly validates and sanitizes input parameters, particularly those used in file inclusion operations. Organizations should also implement proper input validation at multiple layers, including application-level sanitization and the use of allowlists for acceptable language parameters. Additionally, enabling magic_quotes_gpc as a temporary workaround can help prevent exploitation, though this approach is not recommended as a permanent solution due to its deprecation in modern PHP versions. Network-level defenses such as web application firewalls and intrusion detection systems can also help detect and block attempts to exploit this vulnerability by monitoring for suspicious directory traversal patterns in HTTP requests. The vulnerability demonstrates the importance of secure coding practices and input validation, aligning with ATT&CK technique T1059.007 for command and scripting interpreter and T1566.001 for credential access through exploitation of vulnerable applications.