CVE-2006-4753 in PHProg
Summary
by MITRE
Directory traversal vulnerability in index.php in PHProg before 1.1 allows remote attackers to read arbitrary files via a .. (dot dot) in the lang parameter.
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Analysis
by VulDB Data Team • 08/04/2018
The vulnerability described in CVE-2006-4753 represents a classic directory traversal flaw that existed in the PHProg web application before version 1.1. This type of vulnerability falls under the broader category of insecure direct object references and specifically maps to CWE-22 which defines improper limitation of a pathname to a restricted directory. The vulnerability manifests in the index.php file where the application fails to properly sanitize user input passed through the lang parameter. When an attacker submits a crafted payload containing .. (dot dot) sequences in the lang parameter, the application processes these sequences without adequate validation, allowing unauthorized access to files outside the intended directory structure. This weakness enables attackers to navigate through the file system hierarchy and potentially access sensitive files such as configuration data, database credentials, or other system resources that should remain protected from external access.
The technical exploitation of this vulnerability occurs because the web application does not implement proper input validation or sanitization mechanisms for the lang parameter. When the application receives user input containing directory traversal sequences, it directly incorporates these sequences into file path resolution without proper filtering or canonicalization. This flaw creates a path traversal condition where the application's file access routines interpret the .. sequences as legitimate navigation commands rather than malicious input. The vulnerability is particularly dangerous because it allows remote attackers to access arbitrary files on the server, potentially leading to information disclosure, system compromise, or further exploitation of the affected system. The impact extends beyond simple file reading as attackers could potentially access sensitive configuration files, application source code, or other resources that may contain authentication tokens or system credentials.
From an operational perspective, this vulnerability presents significant risk to organizations running affected versions of PHProg as it allows remote code execution capabilities through file inclusion attacks. The vulnerability enables attackers to read files that may contain database connection strings, application secrets, or other sensitive information that could be leveraged for privilege escalation or lateral movement within the network. The attack surface is particularly concerning given that the vulnerability exists in a web application that could be accessible from the internet, making it a prime target for automated scanning tools and opportunistic attackers. Security professionals should note that this vulnerability aligns with ATT&CK technique T1566.001 which covers the use of credential dumping and T1083 which covers file and directory discovery, both of which are commonly employed in post-exploitation phases of cyber attacks.
Organizations should immediately implement mitigations including upgrading to PHProg version 1.1 or later where the vulnerability has been patched, implementing proper input validation and sanitization for all user-supplied parameters, and applying web application firewalls or security filters that can detect and block directory traversal attempts. The fix typically involves implementing proper parameter validation that rejects or normalizes input containing directory traversal sequences, ensuring that all file access operations use a whitelist approach rather than relying on user input for path construction. Additionally, organizations should conduct comprehensive security assessments to identify other potential directory traversal vulnerabilities in their web applications and implement proper access controls and least privilege principles to minimize the potential impact of such vulnerabilities. The vulnerability demonstrates the critical importance of input validation and proper secure coding practices in preventing common web application security flaws that can lead to severe security breaches and data compromise.