CVE-2002-2318 in Falcon Web Server
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Falcon web server 2.0.0.1009 through 2.0.0.1021 allows remote attackers to inject arbitrary web script or HTML via the URI, which is inserted into 301 error messages and executed by 404 error messages.
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Analysis
by VulDB Data Team • 08/28/2025
The vulnerability described in CVE-2002-2318 represents a classic cross-site scripting flaw within the Falcon web server software version range 2.0.0.1009 through 2.0.0.1021. This particular weakness falls under the category of CWE-79 - Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to properly sanitize user input before incorporating it into web content. The vulnerability manifests when the web server processes URIs containing malicious script content that gets embedded into 301 redirect error messages and subsequently executed within 404 error page contexts. This creates a dangerous scenario where attackers can craft specially formatted URLs that, when accessed, trigger the execution of malicious JavaScript code in the victim's browser.
The technical exploitation of this vulnerability occurs through the manipulation of URI parameters that are not properly sanitized by the Falcon web server. When a user accesses a malformed URI, the server generates a 301 redirect response containing the unsanitized input in its error message construction. Subsequently, when the user's browser encounters a 404 error due to the invalid resource, the malicious script embedded in the URI gets executed within the context of the victim's browser session. This represents a sophisticated attack vector that leverages the server's error handling mechanisms to deliver malicious payloads, making it particularly dangerous as it can be triggered through normal web browsing activities without requiring any special privileges or complex attack scenarios.
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, data exfiltration, and redirection to malicious sites. The vulnerability affects all users of the affected Falcon web server versions, creating a widespread security risk for organizations relying on this software stack. Given that the flaw exists in the server's error handling code rather than in the application logic itself, it represents a fundamental security weakness that could be exploited across multiple web applications hosted on the same server infrastructure. This vulnerability aligns with ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, as it enables attackers to deliver malicious payloads through web-based attack vectors that can be easily propagated via phishing campaigns or social engineering.
Organizations affected by this vulnerability should immediately implement mitigations including input validation and sanitization of all URI parameters, proper escaping of user-supplied data in error messages, and updating to patched versions of the Falcon web server software. The recommended approach involves implementing strict input validation that filters out potentially malicious characters and patterns, ensuring that all user-provided data is properly escaped before being incorporated into server-generated error messages. Additionally, organizations should consider implementing web application firewalls and security monitoring solutions that can detect and block suspicious URI patterns. The vulnerability demonstrates the critical importance of secure error handling practices and the need for comprehensive input validation across all web server components, particularly those involved in generating dynamic error messages that may be displayed to end users.