CVE-2007-4957 in Chupix
Summary
by MITRE
Multiple directory traversal vulnerabilities in download.php in Chupix CMS 0.2.3 allow remote attackers to read or overwrite arbitrary files via a .. (dot dot) in the (1) fichier or (2) repertoire parameter, or create arbitrary directories via a .. (dot dot) in the (3) repertoire parameter.
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Analysis
by VulDB Data Team • 10/07/2024
The CVE-2007-4957 vulnerability represents a critical directory traversal flaw in Chupix CMS version 0.2.3 that exposes the system to remote code execution and unauthorized file access. This vulnerability specifically affects the download.php script which handles file operations through three distinct parameters: fichier, repertoire, and a third repertoire parameter. The flaw stems from inadequate input validation and sanitization mechanisms that fail to properly filter or restrict directory path traversal sequences. Attackers can exploit this weakness by injecting .. (dot dot) sequences into these parameters to navigate outside the intended directory boundaries and access or manipulate files outside the web root or designated content directories.
The technical exploitation of this vulnerability occurs through manipulation of HTTP request parameters that are directly passed to file system operations without proper validation. When the fichier or repertoire parameters contain directory traversal sequences, the application processes these inputs without adequate sanitization, allowing attackers to specify absolute paths or navigate to arbitrary locations within the file system. The vulnerability is particularly dangerous because it affects multiple parameter vectors, providing attackers with several potential attack paths to achieve their objectives. The third repertoire parameter adds additional complexity as it allows for directory creation operations, potentially enabling attackers to establish persistent access points or create malicious directories within the target system.
The operational impact of this vulnerability extends beyond simple file reading capabilities to include full system compromise potential. Remote attackers can leverage this weakness to read sensitive configuration files, database credentials, application source code, or other confidential information stored on the server. The ability to overwrite arbitrary files opens the door to code injection attacks where attackers can modify critical application files or replace legitimate executables with malicious payloads. Additionally, the capability to create arbitrary directories allows attackers to establish persistent footholds within the system or create symbolic links that could be exploited for privilege escalation. This vulnerability fundamentally undermines the security boundary between the web application and the underlying operating system, potentially enabling complete system compromise.
Mitigation strategies for CVE-2007-4957 should focus on implementing proper input validation and sanitization mechanisms throughout the application. The most effective approach involves implementing strict parameter validation that rejects or filters out directory traversal sequences including .., %2e%2e, and other encoded variants. Application developers should employ absolute path validation techniques that ensure all file operations occur within predetermined safe directories, implementing whitelist validation for all user-supplied input. The system should also implement proper access controls and privilege separation to limit the impact of potential exploitation. Organizations should consider implementing web application firewalls that can detect and block directory traversal attack patterns, while also ensuring that all legacy applications are properly patched or migrated to modern secure frameworks. This vulnerability aligns with CWE-22 Directory Traversal and represents a common pattern of insecure input handling that has been consistently documented in the security community since the early days of web application development, making it a prime example of the importance of proper input validation and secure coding practices.
The attack surface for this vulnerability demonstrates how seemingly simple parameter handling can create catastrophic security implications. The fact that three different parameters are affected increases the probability of successful exploitation and provides multiple attack vectors for threat actors. This vulnerability serves as a reminder of the critical importance of input validation and the principle of least privilege in web application security. Security practitioners should recognize that directory traversal vulnerabilities often indicate broader issues with application security architecture and recommend comprehensive security assessments to identify similar weaknesses in other application components. The vulnerability also highlights the need for regular security updates and patch management processes, as this particular issue existed in a relatively old version of the CMS and could have been resolved through proper maintenance practices.