CVE-2000-0302 in Index Server
Summary
by MITRE
Microsoft Index Server allows remote attackers to view the source code of ASP files by appending a %20 to the filename in the CiWebHitsFile argument to the null.htw URL.
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Analysis
by VulDB Data Team • 10/16/2025
Microsoft Index Server contains a directory traversal vulnerability that allows remote attackers to access sensitive ASP source code files through a specific URL manipulation technique. This vulnerability exists in the way the system processes the CiWebHitsFile argument within the null.htw URL handler, where the application fails to properly validate or sanitize input parameters before processing file requests. The flaw specifically manifests when an attacker appends a URL-encoded space character %20 to the filename parameter, enabling unauthorized access to web content that should remain protected.
The technical implementation of this vulnerability stems from improper input validation within the Index Server's web hit tracking mechanism. When the CiWebHitsFile parameter is processed, the system does not adequately filter or restrict the file path specification, allowing an attacker to manipulate the request and traverse the file system to access ASP source code files. This represents a classic directory traversal vulnerability that falls under the CWE-22 category for improper limitation of a pathname to a restricted directory. The vulnerability operates at the application layer and can be exploited without authentication, making it particularly dangerous for web applications that store sensitive code in publicly accessible directories.
The operational impact of this vulnerability extends beyond simple code exposure, as ASP source code often contains database connection strings, authentication credentials, and application logic that could be exploited by malicious actors. Attackers can leverage this weakness to gain insights into the application architecture, identify potential security gaps, and develop more sophisticated attack vectors. The vulnerability affects organizations running Microsoft Index Server versions that have not implemented proper input validation controls, potentially exposing sensitive business logic and configuration details that could be used for further exploitation. This weakness directly aligns with ATT&CK technique T1213.002 for Data from Information Repositories, where adversaries extract sensitive information from web applications.
Organizations should implement immediate mitigations including input validation and sanitization of all parameters passed to web hit tracking mechanisms, proper file access controls, and regular updates to Microsoft Index Server installations. The recommended approach involves configuring the web server to reject requests containing suspicious path traversal sequences and implementing proper access controls that prevent unauthorized file system access. Additionally, organizations should consider disabling unnecessary web hit tracking features when they are not actively needed, as this reduces the attack surface. Security monitoring should include detection of URL-encoded sequences in web requests, particularly those containing %20 or other encoding patterns that may indicate directory traversal attempts. The vulnerability highlights the importance of following secure coding practices and implementing proper input validation as outlined in OWASP Top Ten security guidelines.