CVE-2002-1497 in Null HTTP Server
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Null HTTP Server 0.5.0 and earlier allows remote attackers to insert arbitrary HTML into a "404 Not Found" response.
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Analysis
by VulDB Data Team • 09/05/2025
The CVE-2002-1497 vulnerability represents a classic cross-site scripting flaw within the Null HTTP Server version 0.5.0 and earlier implementations. This vulnerability specifically targets the server's handling of HTTP 404 Not Found responses, where the application fails to properly sanitize user input before incorporating it into the error page content. The flaw exists in the server's response generation mechanism, where it directly embeds user-supplied data into HTML responses without adequate validation or encoding measures.
The technical exploitation of this vulnerability occurs when remote attackers craft malicious HTTP requests that trigger a 404 response from the affected server. The server's inadequate input sanitization allows attackers to inject arbitrary HTML code into the error page, which then gets executed by the victim's browser when the page is rendered. This represents a Type 1 cross-site scripting vulnerability where the malicious input originates from the server's own response content rather than from user-provided form data or URL parameters. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws where untrusted data is incorporated into web pages without proper validation or encoding.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it can enable attackers to execute malicious scripts in the context of the victim's browser session. This opens possibilities for session hijacking, credential theft, and the delivery of additional malware payloads. The vulnerability is particularly concerning because it affects the fundamental error handling mechanism of the web server, meaning that any user interaction with the server could potentially trigger the malicious code execution. Attackers can leverage this to create persistent XSS attacks that compromise user sessions and potentially escalate privileges within the web application environment.
Mitigation strategies for CVE-2002-1497 should focus on implementing proper input validation and output encoding mechanisms within the server's response handling. Organizations should ensure that all user-supplied data is properly sanitized before inclusion in any HTML response, particularly in error pages where such data might be displayed. The implementation of Content Security Policy headers can provide additional protection against XSS attacks by limiting the sources from which scripts can be executed. Regular security updates and patches should be applied to ensure that the Null HTTP Server is running a version that addresses this vulnerability, as the flaw represents a fundamental security weakness in the server's architecture that could be exploited for more sophisticated attacks. This vulnerability demonstrates the importance of secure coding practices and proper input validation in web server implementations, as highlighted by ATT&CK technique T1212 which focuses on exploitation of software vulnerabilities for privilege escalation and persistent access.