CVE-2002-0200 in Web Server
Summary
by MITRE
Cyberstop Web Server for Windows 0.1 allows remote attackers to cause a denial of service via an HTTP request for an MS-DOS device name.
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Analysis
by VulDB Data Team • 09/22/2025
The vulnerability identified as CVE-2002-0200 affects the Cyberstop Web Server version 0.1 running on Windows operating systems. This security flaw represents a classic denial of service condition that can be exploited by remote attackers through carefully crafted HTTP requests. The vulnerability specifically targets the server's handling of requests for MS-DOS device names, which are special device file references used by the Windows operating system. These device names include references such as CON, PRN, AUX, NUL, and COM1 through COM9, among others, which are reserved for system devices and should not be accessible through standard file system operations.
The technical mechanism behind this vulnerability stems from the web server's inadequate input validation and processing of HTTP requests. When the server receives an HTTP request containing a path that references an MS-DOS device name, it fails to properly sanitize or reject such requests before attempting to process them. The server's internal logic likely attempts to resolve or access these device references as if they were regular files, leading to system-level resource exhaustion or process termination. This occurs because the web server's file handling routines do not properly distinguish between legitimate file requests and system device references that should be blocked at the protocol level. The flaw demonstrates poor security design principles and inadequate boundary checking in the server's request processing pipeline, making it susceptible to exploitation through malformed requests that trigger unexpected system behavior.
The operational impact of this vulnerability extends beyond simple service disruption, as it represents a fundamental weakness in the web server's security architecture that could potentially be leveraged for more sophisticated attacks. Remote attackers can exploit this vulnerability without requiring authentication or prior access to the system, making it particularly dangerous in publicly accessible environments. The denial of service condition can result in complete unavailability of the web server, impacting legitimate users and potentially causing business disruption. From an attacker's perspective, this vulnerability provides a straightforward method to compromise service availability, which could be used as part of larger attack campaigns or as a means to mask other malicious activities. The vulnerability also highlights the importance of proper input validation and the need for web servers to implement robust security measures that prevent access to system-reserved resources.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and access control measures. System administrators should immediately apply available patches or updates from the vendor to address this specific flaw, as the vulnerability is well-documented and likely has a readily available fix. Network-level protections such as intrusion detection systems and firewalls can be configured to block requests containing known MS-DOS device name patterns, providing an additional layer of defense. The implementation of web application firewalls can also help filter out malicious requests before they reach the web server. Additionally, the server configuration should be reviewed to ensure that access to system-reserved device names is explicitly denied through proper access control lists and file system permissions. This vulnerability aligns with CWE-20, which describes improper input validation, and could potentially be mapped to ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also consider implementing monitoring and logging mechanisms to detect suspicious requests that attempt to access system device names, as this behavior may indicate attempted exploitation of similar vulnerabilities. Regular security assessments and penetration testing should be conducted to identify and remediate similar weaknesses in web server configurations and input handling processes.