CVE-2002-1053 in Jigsaw
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in W3C Jigsaw Proxy Server before 2.2.1 allows remote attackers to execute arbitrary script via a URL that contains a reference to a nonexistent host followed by the script, which is included in the resulting error message.
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Analysis
by VulDB Data Team • 09/10/2025
The CVE-2002-1053 vulnerability represents a classic cross-site scripting flaw in the W3C Jigsaw Proxy Server version 2.2.0 and earlier. This security weakness arises from the server's inadequate handling of malformed URLs containing references to nonexistent hosts. When a user attempts to access a URL that points to a non-existent domain, the proxy server generates an error message that includes the malformed URL in its output without proper sanitization. This behavior creates a direct injection vector where malicious actors can embed arbitrary script code within the URL structure, specifically in the host portion, which then gets rendered in the error message displayed to users.
The technical exploitation of this vulnerability follows a specific pattern where attackers craft URLs containing script code within the host parameter of the requested resource. When the proxy server attempts to resolve this nonexistent host and generates an error page, it incorporates the malformed URL directly into the HTML output without proper encoding or filtering. This process violates fundamental security principles of input validation and output sanitization, allowing malicious scripts to execute in the context of the victim's browser session. The vulnerability is classified under CWE-79 as a failure to sanitize or incorrectly sanitizes user-provided data, making it susceptible to cross-site scripting attacks.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to perform various malicious activities including session hijacking, credential theft, and data exfiltration. When users encounter the error message containing the injected script, the malicious code executes within their browser, potentially compromising their session cookies, personal information, or system access. This vulnerability particularly affects organizations relying on the W3C Jigsaw Proxy Server for web access control, as it undermines the security posture of the entire proxy infrastructure. The attack vector is straightforward and requires minimal technical expertise, making it a significant threat to web applications that depend on vulnerable proxy implementations.
Organizations affected by this vulnerability should implement immediate mitigations including upgrading to W3C Jigsaw Proxy Server version 2.2.1 or later, which contains the necessary fixes for proper input sanitization. Additionally, administrators should configure the proxy server to sanitize all user-provided input before generating error messages, implementing proper HTML encoding for dynamic content. Network-level protections such as web application firewalls can provide additional defense-in-depth measures. The vulnerability aligns with ATT&CK technique T1203, which covers exploitation of web application vulnerabilities, and demonstrates the importance of proper input validation as outlined in the OWASP Top Ten security principles. Regular security assessments and patch management processes should be implemented to prevent similar vulnerabilities in other web applications and proxy systems.