CVE-2004-0245 in Web Crossing
Summary
by MITRE
Web Crossing 4.x and 5.x allows remote attackers to cause a denial of service (crash) by sending a HTTP POST request with a large or negative Content-Length, which causes an integer divide-by-zero.
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Analysis
by VulDB Data Team • 08/17/2025
The vulnerability identified as CVE-2004-0245 affects Web Crossing versions 4.x and 5.x, representing a critical denial of service flaw that can be exploited remotely. This issue stems from insufficient input validation within the web server's handling of HTTP POST requests, specifically when processing the Content-Length header field. The vulnerability operates through a classic integer overflow or division by zero condition that occurs when an attacker crafts a malicious HTTP request containing an excessively large or negative Content-Length value. Such malformed requests can trigger unpredictable behavior in the application's memory management and request processing logic, ultimately leading to application crashes and service unavailability.
The technical exploitation of this vulnerability involves sending an HTTP POST request where the Content-Length header contains either a value that exceeds the maximum integer limit or a negative value that cannot be properly processed by the server's internal arithmetic operations. When the web server attempts to perform division operations using this invalid Content-Length value, particularly in calculations related to request body processing or buffer allocation, it encounters a divide-by-zero condition that causes the application to terminate abruptly. This type of flaw falls under the Common Weakness Enumeration category CWE-369, which specifically addresses the divide by zero weakness in software implementations. The vulnerability represents a fundamental failure in input sanitization and error handling mechanisms within the web server's HTTP protocol parsing layer.
The operational impact of CVE-2004-0245 extends beyond simple service disruption, as it can be leveraged by remote attackers to systematically crash the web server and render hosted services inaccessible to legitimate users. This denial of service condition affects not only the immediate availability of web applications but also potentially impacts the broader network infrastructure if the affected server serves as a critical component in the application delivery chain. Attackers can exploit this vulnerability with minimal technical expertise, requiring only basic HTTP request construction tools, making it particularly dangerous in production environments where such attacks can be automated and executed at scale. The vulnerability demonstrates poor adherence to secure coding practices and highlights the importance of proper input validation and error handling in network services. From an adversarial perspective, this flaw aligns with ATT&CK technique T1499.004, which involves network denial of service attacks through resource exhaustion or application crashes, making it a valuable target for attackers seeking to disrupt web-based services.
Mitigation strategies for this vulnerability require immediate patching of affected Web Crossing installations to the latest available versions that contain proper input validation for Content-Length headers. System administrators should implement network-level protections such as intrusion detection systems that can identify and block suspicious HTTP requests containing malformed Content-Length values. Additionally, configuring web servers to reject requests with invalid or suspicious header values can provide an additional layer of defense. The vulnerability underscores the necessity of implementing comprehensive input validation routines that check for both positive and negative integer values in HTTP headers, as well as proper error handling that prevents arithmetic exceptions from causing application termination. Organizations should also consider implementing rate limiting and request size restrictions to minimize the impact of potential exploitation attempts. Regular security assessments and code reviews focusing on input validation and error handling practices can help identify similar vulnerabilities in other applications and prevent future incidents of this nature.