CVE-2006-4503 in NX5Linx
Summary
by MITRE
Directory traversal vulnerability in link.php in NX5Linx 1.0 allows remote attackers to read arbitrary files via the logo parameter.
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Analysis
by VulDB Data Team • 08/03/2018
The vulnerability identified as CVE-2006-4503 represents a critical directory traversal flaw within the NX5Linx 1.0 web application, specifically affecting the link.php script. This vulnerability stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data before processing. The affected parameter, named logo, accepts arbitrary input that can be manipulated to navigate the file system beyond the intended directory structure. When an attacker submits malicious input through this parameter, the application processes the request without proper boundary checks, allowing unauthorized access to files outside the web root directory.
This directory traversal vulnerability directly maps to CWE-22, which defines the weakness of improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal. The flaw enables attackers to exploit the application's file handling mechanisms by crafting malicious requests that leverage directory navigation sequences such as ../ or ..\ to move up the directory tree. The vulnerability exists due to the application's failure to implement proper input validation and sanitization, creating an attack surface where remote adversaries can access sensitive files including configuration files, database credentials, system files, and other confidential data that should remain protected from unauthorized access.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with the capability to read arbitrary files from the affected system. Remote attackers can leverage this vulnerability to access critical system information, potentially obtaining database connection strings, application configuration files, user credentials, and other sensitive data that could lead to further system compromise. The vulnerability affects the confidentiality and integrity of the affected web application, as unauthorized file access can result in data leakage, system reconnaissance, and potential escalation to privilege escalation attacks. Additionally, the vulnerability may enable attackers to discover other applications or services running on the same system through the exposure of configuration files and system information.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1566, which encompasses credential access and reconnaissance activities through the exploitation of web application vulnerabilities. The attack chain typically begins with reconnaissance to identify the vulnerable application, followed by crafting malicious requests to exploit the directory traversal flaw. The remediation strategy should focus on implementing proper input validation and sanitization mechanisms, specifically ensuring that all user-supplied input is validated against a strict whitelist of acceptable characters and patterns. The application should enforce proper path normalization and validation before processing file operations, eliminating the possibility of directory traversal attacks. Additionally, implementing proper access controls and the principle of least privilege can mitigate the impact of successful exploitation, ensuring that even if an attacker gains access to files, they cannot access sensitive system resources beyond what is necessary for legitimate application functionality. The vulnerability highlights the critical importance of secure coding practices and input validation in web application development, emphasizing the need for comprehensive security testing and code review processes to identify and remediate similar flaws before they can be exploited by malicious actors.