CVE-2003-1569 in WebServer
Summary
by MITRE
GoAhead WebServer before 2.1.5 on Windows 95, 98, and ME allows remote attackers to cause a denial of service (daemon crash) via an HTTP request with a (1) con, (2) nul, (3) clock$, or (4) config$ device name in a path component, different vectors than CVE-2001-0385.
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Analysis
by VulDB Data Team • 10/27/2018
The vulnerability described in CVE-2003-1569 represents a classic denial of service flaw in the GoAhead WebServer implementation on legacy Windows operating systems. This issue affects versions prior to 2.1.5 and specifically targets Windows 95, 98, and ME platforms where the web server process becomes unstable when processing HTTP requests containing specific device names in the path component. The flaw demonstrates a fundamental lack of proper input validation and sanitization in the web server's handling of file path requests.
The technical root cause of this vulnerability lies in the web server's improper handling of device names that are reserved in the Windows operating system. When an attacker submits an HTTP request containing device names such as con, nul, clock$, or config$ in the path component, the GoAhead WebServer attempts to process these requests without adequate validation. These device names represent special reserved names in Windows that are used for system devices and are typically protected from direct file access. The web server's failure to recognize these names as invalid path components leads to a crash when the system attempts to resolve or access these pseudo-devices, resulting in a complete daemon crash and denial of service condition.
This vulnerability operates through multiple attack vectors that differ from the previously identified CVE-2001-0385, indicating a broader class of input validation issues within the web server's path handling logic. The specific device names mentioned in the vulnerability are part of the Windows reserved device names that include con, aux, prn, nul, and various clock$ and config$ variations that are used for system management and device access. When these names appear in the path component of HTTP requests, the web server's internal file resolution mechanisms fail to properly reject them, leading to the daemon crashing and becoming unavailable to legitimate users.
The operational impact of this vulnerability extends beyond simple service disruption as it represents a critical weakness in the web server's security architecture. An attacker can reliably cause the web server daemon to crash by simply crafting a malformed HTTP request containing these device names, making it a straightforward denial of service attack that requires minimal technical expertise. The vulnerability affects systems running older Windows versions where the operating system's device name validation is not properly enforced at the application layer, creating a scenario where application-level code must handle the responsibility of validating input that should be handled at the OS level.
From a cybersecurity perspective, this vulnerability aligns with CWE-20, which describes improper input validation in software systems, and demonstrates the importance of defense in depth principles in web server configurations. The issue also relates to ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion or daemon crashes. Organizations running legacy systems with vulnerable GoAhead WebServer versions face significant operational risks as this vulnerability can be exploited by anyone with network access to the affected systems, potentially leading to extended service outages and business disruption.
The recommended mitigations for this vulnerability include immediate upgrading to GoAhead WebServer version 2.1.5 or later, which contains proper input validation for device names in path components. Additionally, implementing network-level restrictions to filter out requests containing these specific device names can provide temporary protection while upgrades are being deployed. System administrators should also consider implementing monitoring solutions to detect anomalous HTTP request patterns that may indicate exploitation attempts, as well as establishing incident response procedures for handling denial of service events. The vulnerability underscores the critical importance of keeping web server software updated and maintaining proper input validation practices throughout the application stack.