CVE-2002-1031 in KF Web Server
Summary
by MITRE
KeyFocus (KF) web server 1.0.2 allows remote attackers to list directories and read restricted files via an HTTP request containing a %00 (null) character.
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Analysis
by VulDB Data Team • 09/10/2025
The vulnerability identified as CVE-2002-1031 affects KeyFocus web server version 1.0.2, representing a critical security flaw that enables remote attackers to bypass access controls and gain unauthorized access to sensitive system information. This vulnerability stems from improper input validation within the web server's handling of HTTP requests, specifically when processing null character sequences. The flaw allows malicious actors to manipulate HTTP requests by injecting %00 characters, which are interpreted as null terminators in certain programming contexts, potentially leading to buffer overflows or path traversal attacks.
The technical mechanism behind this vulnerability involves the web server's failure to properly sanitize input parameters containing null characters. When a request containing a %00 character is processed, the server may interpret this null byte as a string terminator, causing it to truncate paths or bypass security checks that would normally prevent directory listing or file access. This behavior aligns with common buffer overflow patterns and input validation bypass techniques that have been documented in various security frameworks. The vulnerability essentially allows attackers to craft requests that circumvent the web server's normal access control mechanisms, enabling them to enumerate directories and read files that should otherwise be restricted.
From an operational impact perspective, this vulnerability poses significant risks to organizations relying on KeyFocus web server 1.0.2 for hosting sensitive content or applications. Remote attackers can exploit this flaw to discover the directory structure of web applications, access configuration files, source code, or other sensitive data that may contain credentials, database connection strings, or other proprietary information. The potential for information disclosure and system reconnaissance makes this vulnerability particularly dangerous as it can serve as a foundation for more sophisticated attacks. According to the Common Weakness Enumeration catalog, this vulnerability maps to weakness category CWE-125, which covers out-of-bounds read conditions, and CWE-22, which addresses path traversal vulnerabilities. The attack vector can be classified under ATT&CK technique T1083, which covers directory listing, and T1213, which covers data from information repositories.
Mitigation strategies for CVE-2002-1031 should prioritize immediate patching or upgrading of affected KeyFocus web server installations to versions that properly handle null character inputs. Organizations should implement input validation mechanisms that explicitly filter or reject null byte sequences in HTTP requests, particularly in URI paths and query parameters. Network-level defenses such as web application firewalls can be configured to detect and block requests containing null characters. Additionally, system administrators should conduct thorough security audits to identify and remove any unnecessary directory listings or file access permissions that could be exploited through this vulnerability. The remediation process should also include implementing proper access controls and ensuring that only authorized users can access sensitive system resources, as this vulnerability fundamentally undermines the web server's ability to enforce access restrictions. Regular security testing and vulnerability assessments should be conducted to identify similar input validation flaws in other web server components or applications that may be susceptible to similar attacks.