CVE-2001-0303 in Pi3Web
Summary
by MITRE
tstisapi.dll in Pi3Web 1.0.1 web server allows remote attackers to determine the physical path of the server via a URL that requests a non-existent file.
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Analysis
by VulDB Data Team • 05/12/2019
The vulnerability described in CVE-2001-0303 represents a classic information disclosure flaw within the Pi3Web 1.0.1 web server implementation. This issue specifically affects the tstisapi.dll component which handles isapi requests, creating a pathway for remote attackers to enumerate the physical file system structure of the affected server. The vulnerability manifests when users attempt to access non-existent files through the web interface, causing the server to inadvertently reveal directory paths and file locations in its error responses.
The technical nature of this flaw stems from improper error handling within the isapi extension module. When a request is made for a non-existent resource, the system fails to sanitize its error messages properly, instead exposing detailed path information that includes the absolute physical path where the web server is installed. This behavior creates a significant information disclosure risk that directly violates security best practices for error message handling and system hardening. The vulnerability operates at the application layer and can be exploited without authentication, making it particularly dangerous for publicly accessible web servers.
The operational impact of this vulnerability extends beyond simple path disclosure, as it provides attackers with crucial reconnaissance data that can be leveraged for more sophisticated attacks. Knowledge of the physical server paths enables attackers to craft more targeted exploitation strategies, potentially leading to directory traversal attacks, local file inclusion vulnerabilities, or further enumeration of system resources. This information disclosure represents a fundamental breakdown in the principle of least privilege and can significantly reduce the security posture of the affected system. The vulnerability aligns with CWE-200, which specifically addresses information exposure, and demonstrates poor input validation and error handling practices that are commonly exploited in web application attacks.
Mitigation strategies for this vulnerability should focus on implementing proper error handling mechanisms that do not expose system paths to remote users. Organizations should configure their web servers to return generic error messages that do not contain sensitive path information. The recommended approach involves modifying the error response handling within the isapi extension to sanitize all error messages and prevent path disclosure. Additionally, implementing proper access controls, regular security updates, and comprehensive monitoring systems can help detect and prevent exploitation attempts. This vulnerability also highlights the importance of adhering to security standards such as those outlined in the OWASP Top Ten and demonstrates how basic security misconfigurations can create significant exposure points in web infrastructure. The issue serves as a reminder of the critical importance of secure coding practices and proper error handling in web application development.