CVE-2002-0099 in Savant Webserver
Summary
by MITRE
Buffer overflow in Michael Lamont Savant Web Server 3.0 allows remote attackers to cause a denial of service (crash) via a long HTTP request to the cgi-bin directory in which the CGI program name contains a large number of . (dot) characters.
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Analysis
by VulDB Data Team • 05/18/2019
The vulnerability identified as CVE-2002-0099 represents a critical buffer overflow flaw within the Savant Web Server version 3.0 that exposes systems to remote exploitation. This issue specifically manifests when the web server processes HTTP requests directed toward the cgi-bin directory where the CGI program name contains an excessive number of dot characters. The flaw stems from inadequate input validation and memory management within the server's handling of file paths, creating a condition where the buffer allocated for processing these paths becomes overwhelmed by the excessive dot character sequence. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The vulnerability demonstrates characteristics consistent with the ATT&CK technique T1499.004 for network denial of service, as it directly enables remote attackers to crash the web server service.
The technical implementation of this vulnerability exploits the server's failure to properly validate the length of CGI program names within the cgi-bin directory. When a malicious HTTP request is crafted with an excessive number of consecutive dot characters in the CGI filename, the web server's internal buffer handling mechanism fails to accommodate the input size, resulting in memory corruption. The buffer overflow occurs during the parsing of the requested resource path, where the server attempts to construct the full path to the CGI program without sufficient bounds checking on the dot character count. This flaw is particularly dangerous because it requires minimal privileges to exploit, as attackers only need to send a specially crafted HTTP request to the vulnerable server. The server's response to such malformed requests is immediate and deterministic, causing a crash that results in complete service unavailability.
The operational impact of CVE-2002-0099 extends beyond simple service disruption to encompass potential system compromise and broader network availability issues. When exploited successfully, the buffer overflow causes the Savant Web Server to terminate unexpectedly, leading to a complete denial of service for all users accessing the affected web applications. This type of vulnerability is particularly concerning for web servers hosting critical business applications, as it can result in significant financial losses and reputational damage. The vulnerability affects not only the immediate web server but also any systems dependent on its services, creating cascading effects throughout the network infrastructure. Organizations running this version of the Savant Web Server are particularly vulnerable as the flaw exists in the core request processing logic, making it extremely difficult to patch without complete server replacement or major software updates.
Mitigation strategies for CVE-2002-0099 require immediate action to address the underlying buffer overflow condition. The most effective approach involves upgrading to a patched version of the Savant Web Server that includes proper input validation and bounds checking for file path processing. System administrators should implement network-level protections such as firewall rules that restrict access to cgi-bin directories or implement rate limiting to prevent exploitation attempts. Additionally, the implementation of intrusion detection systems can help identify malicious traffic patterns associated with this vulnerability. Organizations should also consider implementing web application firewalls that can detect and block requests containing excessive dot characters in CGI paths. The vulnerability highlights the importance of secure coding practices and input validation, particularly in web server implementations where user-supplied data directly influences memory allocation and processing. Regular security assessments and vulnerability scanning should be conducted to identify similar buffer overflow conditions in other server components and applications.