CVE-2000-0014 in Savant WebServer
Summary
by MITRE
Denial of service in Savant web server via a null character in the requested URL.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 10/20/2025
The CVE-2000-0014 vulnerability represents a classic denial of service flaw in the Savant web server implementation that exploits how the server processes URL requests containing null characters. This vulnerability stems from the server's inadequate input validation mechanisms that fail to properly handle null bytes within requested URLs, creating a condition where legitimate requests can trigger unexpected server behavior leading to complete service disruption. The flaw specifically manifests when a client sends a request containing a null character within the URL path or query string, causing the web server to malfunction and terminate its ability to process subsequent requests.
The technical root cause of this vulnerability lies in the server's string handling routines that do not properly sanitize input data before processing. When a null character is encountered within a URL, the Savant web server's internal string parsing functions may interpret this as a string termination signal, causing memory corruption or unexpected program flow that ultimately results in the server crashing or becoming unresponsive. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, though in this specific case the impact is more accurately described as a denial of service rather than arbitrary code execution. The vulnerability demonstrates poor input validation practices that are common in legacy web server implementations where developers did not account for all possible character sequences that could be transmitted through HTTP requests.
The operational impact of CVE-2000-0014 is significant as it allows an attacker to completely disrupt web services hosted on affected Savant servers without requiring any privileged access or authentication. The vulnerability can be exploited through simple HTTP requests containing null characters in the URL, making it easily accessible to anyone with network connectivity to the target server. This creates a scenario where a single malicious request can render an entire web service unavailable to legitimate users, effectively causing a denial of service condition that can persist until the server is manually restarted or the vulnerable process is terminated. The impact extends beyond simple service interruption as it can be used in conjunction with other attack vectors to create more sophisticated denial of service campaigns that can overwhelm server resources and potentially cause cascading failures in dependent systems.
Security practitioners should implement multiple layers of mitigation strategies to address this vulnerability, starting with immediate patching of affected Savant server installations to ensure proper null character handling in URL processing. Network-level protections can include implementing web application firewalls that filter out requests containing null characters or other suspicious input patterns, though such solutions should be carefully tested to avoid blocking legitimate traffic. Input validation should be strengthened at multiple points including the web server itself, application level filters, and proxy servers that may sit between clients and the vulnerable server. Organizations should also consider implementing monitoring systems that can detect unusual request patterns or service disruptions that may indicate exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique of network denial of service, and the mitigation strategies should align with defensive measures outlined in the command and control and persistence domains to prevent exploitation and maintain service availability.