CVE-2002-1828 in Webserver
Summary
by MITRE
Savant Webserver 3.1 allows remote attackers to cause a denial of service (crash) via an HTTP GET request with a negative Content-Length value.
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Analysis
by VulDB Data Team • 05/02/2025
The vulnerability identified as CVE-2002-1828 affects the Savant Webserver version 3.1 and represents a classic denial of service flaw that exploits improper input validation mechanisms. This issue arises from the web server's failure to properly handle malformed HTTP requests, specifically those containing negative values in the Content-Length header field. The vulnerability falls under the category of improper input validation, which is classified as CWE-20 by the Common Weakness Enumeration framework. Attackers can leverage this weakness by crafting specially formatted HTTP GET requests that include a negative Content-Length value, causing the web server to crash and become unavailable to legitimate users.
The technical implementation of this vulnerability stems from the web server's insufficient validation of HTTP headers during request processing. When the Savant Webserver receives an HTTP GET request with a negative Content-Length value, it fails to properly parse or reject this invalid header field. The server's parsing logic does not account for negative values in the Content-Length field, which should logically be a non-negative integer representing the size of the request body. This parsing failure leads to unpredictable behavior within the server's memory management and request handling routines, ultimately resulting in a crash or complete service disruption. The vulnerability is particularly concerning because it requires no authentication or special privileges to exploit, making it accessible to any remote attacker with network connectivity to the affected server.
From an operational perspective, this vulnerability creates significant risk for organizations relying on the Savant Webserver for their web hosting services. The denial of service condition can result in complete unavailability of the web application or service, potentially affecting business operations and customer access. The impact extends beyond simple service interruption as the crash may also lead to potential data loss or corruption if the server does not handle the abrupt termination gracefully. Additionally, the vulnerability may serve as an entry point for more sophisticated attacks, as the server crash could be used to mask other malicious activities or to test the overall security posture of the affected system. The attack vector is particularly dangerous because it can be executed remotely without requiring any credentials, and the attack can be automated to target multiple servers simultaneously.
The mitigation strategies for this vulnerability should focus on both immediate remediation and long-term security improvements. The most effective immediate solution involves applying the vendor-provided patch or upgrade to a version of the Savant Webserver that properly validates Content-Length headers and rejects negative values. Organizations should also implement network-level protections such as intrusion detection systems that can identify and block malformed HTTP requests containing negative Content-Length values. Configuration hardening measures should include implementing proper input validation at the network level and deploying web application firewalls that can filter out suspicious HTTP headers. From a defensive standpoint, this vulnerability highlights the importance of adhering to the principle of least privilege and implementing comprehensive monitoring of web server operations. The ATT&CK framework categorizes this type of vulnerability under the 'Resource Exhaustion' tactic, where adversaries seek to consume system resources or cause system instability to deny service to legitimate users. Regular security assessments and vulnerability scanning should be implemented to identify similar input validation flaws in other web server components and applications within the organization's infrastructure.