CVE-2002-2076 in Lil Http
Summary
by MITRE
Directory traversal vulnerability in Lil HTTP server 2.1 and 2.2 allows remote attackers to read arbitrary files via a .. (dot dot) in an HTTP GET request.
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Analysis
by VulDB Data Team • 07/08/2024
The CVE-2002-2076 vulnerability represents a critical directory traversal flaw in the Lil HTTP server versions 2.1 and 2.2, fundamentally compromising the security boundaries of web applications. This vulnerability stems from inadequate input validation within the HTTP request processing mechanism, specifically when handling the .. (dot dot) sequence in GET requests. The flaw allows remote attackers to bypass normal file access controls and retrieve arbitrary files from the server filesystem, potentially exposing sensitive data including configuration files, user credentials, and application source code.
The technical implementation of this vulnerability operates through the exploitation of improper path resolution logic within the HTTP server's file handling routines. When a client submits an HTTP GET request containing directory traversal sequences such as ../../etc/passwd or ../../../windows/system32/drivers/etc/hosts, the server fails to properly sanitize these paths before attempting to access the requested files. This results in the server resolving the malicious paths relative to its root directory, effectively allowing access to files outside the intended web root. The vulnerability directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw demonstrates a classic lack of input sanitization and proper path validation, creating a fundamental security gap in the server's access control mechanisms.
From an operational impact perspective, this vulnerability presents severe consequences for any organization deploying affected Lil HTTP server versions. Attackers can exploit this weakness to access sensitive system files, user databases, application configuration files, and potentially even administrative credentials stored in plain text. The remote nature of the attack means that no local system access is required, making it particularly dangerous for web applications. The vulnerability essentially allows for arbitrary file reading capabilities, which can lead to complete system compromise if sensitive files like database credentials, SSL certificates, or application source code are accessible. This aligns with ATT&CK technique T1213.002 for Credential Access, specifically targeting the extraction of credentials from files, and represents a significant vector for information disclosure attacks.
The mitigation strategies for CVE-2002-2076 primarily involve immediate patching of the affected Lil HTTP server versions to the latest secure releases that properly implement input validation and path sanitization. Organizations should implement proper input validation at multiple layers including application-level sanitization of file paths, web application firewalls that can detect and block directory traversal patterns, and network-level filtering to prevent malicious requests. Additionally, implementing proper access controls through the principle of least privilege ensures that even if an attacker successfully exploits the vulnerability, the damage remains limited. System administrators should also conduct comprehensive file access reviews to identify and secure sensitive files that might be exposed through this vulnerability. The remediation process should include thorough testing to ensure that the patch does not introduce compatibility issues with existing applications while maintaining the server's intended functionality.
Organizations should also consider implementing monitoring and detection mechanisms to identify potential exploitation attempts through log analysis and intrusion detection systems that can flag directory traversal patterns in HTTP requests. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other web applications and servers. The vulnerability underscores the importance of proper input validation and the principle of least privilege in web application security, serving as a reminder of the critical need for robust security controls in all server-side components. This particular flaw represents a foundational security issue that highlights the necessity of addressing basic security principles in web server implementations to prevent unauthorized access to critical system resources.