CVE-2002-1248 in Xeneo Web Server
Summary
by MITRE
Northern Solutions Xeneo Web Server 2.1.0.0, 2.0.759.6, and other versions before 2.1.5 allows remote attackers to cause a denial of service (crash) via a GET request for a "%" URI.
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Analysis
by VulDB Data Team • 04/28/2025
The vulnerability identified as CVE-2002-1248 affects the Northern Solutions Xeneo Web Server versions 2.1.0.0, 2.0.759.6, and other prior releases up to version 2.1.4. This represents a classic denial of service flaw that demonstrates how improper input handling can lead to system instability and service disruption. The vulnerability specifically manifests when the web server processes a GET request containing a "%" character in the URI, causing the server to crash and become unavailable to legitimate users. This type of vulnerability falls under the category of improper input validation, where the server fails to properly sanitize or handle special characters in Uniform Resource Identifiers.
The technical mechanism behind this vulnerability involves the web server's inadequate parsing of URL-encoded characters, particularly the percent sign which is a fundamental component of URI encoding standards. When the server encounters a GET request with a "%" character in the URI path, it fails to properly handle the malformed input, leading to a crash condition that terminates the web server process. This behavior aligns with CWE-129, which describes improper validation of array index values, and CWE-20, which covers input validation issues. The flaw represents a failure in the server's request parsing logic to properly validate and sanitize incoming URI components, particularly those containing special encoding characters.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the availability of web services for legitimate users. An attacker can exploit this weakness by simply sending a crafted GET request containing a percent sign in the URI, causing the web server to crash and restart. This type of attack can be easily automated and executed by anyone with basic network access to the affected server, making it a significant risk for organizations relying on this web server implementation. The vulnerability particularly affects environments where the web server is exposed to untrusted networks or where access controls are inadequate, as it requires minimal technical expertise to exploit successfully.
Mitigation strategies for this vulnerability should focus on both immediate patching and defensive measures. The primary solution involves upgrading to Northern Solutions Xeneo Web Server version 2.1.5 or later, which contains the necessary fixes to properly handle percent-encoded URI components. Organizations should also implement network-level protections such as web application firewalls that can detect and block malformed URI requests before they reach the vulnerable web server. Additionally, administrators should consider implementing rate limiting and access controls to minimize the impact of potential exploitation attempts. This vulnerability demonstrates the importance of proper input validation and adheres to ATT&CK technique T1499.004, which covers network denial of service attacks through malformed requests, emphasizing the need for robust server-side input sanitization to prevent such exploitation vectors.