CVE-2002-0556 in Quik-Serv Webserver
Summary
by MITRE
Directory traversal vulnerability in Quik-Serv HTTP server 1.1B allows remote attackers to read arbitrary files via a .. (dot dot) in a URL.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/16/2025
The CVE-2002-0556 vulnerability represents a classic directory traversal flaw in the Quik-Serv HTTP server version 1.1B, fundamentally compromising the server's ability to properly validate and sanitize incoming URL requests. This vulnerability 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 flaw manifests when the server fails to adequately process or sanitize dot-dot sequences within URL paths, allowing malicious actors to manipulate file access requests and navigate beyond the intended document root directory.
The technical exploitation of this vulnerability occurs when an attacker crafts a URL containing .. (dot dot) sequences that the server processes without proper validation, enabling access to files outside the web server's designated directory structure. This occurs because the server's request handling mechanism does not properly canonicalize or sanitize the URL path before attempting to serve files, allowing attackers to traverse up the directory hierarchy and access sensitive files such as configuration files, system files, or other resources that should remain protected from public access. The vulnerability specifically affects the HTTP server's file serving capabilities and demonstrates a fundamental lack of input validation in the path resolution process.
Operationally, this vulnerability presents a significant risk to systems running Quik-Serv 1.1B, as remote attackers can potentially access critical system information, configuration data, or sensitive files without authentication. The impact extends beyond simple information disclosure, as attackers may gain access to database connection details, administrative credentials, or other sensitive configuration information that could lead to further system compromise. The vulnerability can be exploited from any remote location, making it particularly dangerous in internet-facing environments where the server is accessible to unauthenticated users. This type of attack aligns with the MITRE ATT&CK technique T1566, which involves the exploitation of vulnerabilities in web applications to gain unauthorized access to system resources.
The mitigation strategy for CVE-2002-0556 requires immediate implementation of proper input validation and sanitization mechanisms within the HTTP server's URL processing pipeline. Organizations should ensure that all path traversal attempts are properly detected and blocked by implementing strict path validation that prevents the use of .. sequences or other directory traversal patterns in file access requests. The server configuration should enforce proper directory boundary checks and canonicalize all incoming file paths before attempting to serve content. Additionally, system administrators should consider implementing web application firewalls or security modules that can detect and block suspicious path traversal attempts. The most effective long-term solution involves upgrading to a newer version of the Quik-Serv software that properly addresses this vulnerability or migrating to more modern and secure web server implementations that have robust input validation and sanitization capabilities. Security monitoring should also be enhanced to detect unusual file access patterns that might indicate exploitation attempts.