CVE-1999-0021 is a high-severity vulnerability identified in the Count.cgi program, part of the wwwcount CGI-bin software, version 2.3. The vulnerability arises from a buffer overflow condition within the Count.cgi script, which allows an attacker to execute arbitrary commands on the affected system remotely. Specifically, the flaw exists because the program fails to properly validate or limit input data, enabling an attacker to overwrite memory buffers and inject malicious code. This can lead to full compromise of the web server hosting the vulnerable CGI script, as the attacker can execute commands with the privileges of the web server process. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, making it particularly dangerous. The CVSS v2 score of 7.5 reflects the ease of exploitation (low attack complexity), no authentication required, and the potential for complete confidentiality, integrity, and availability impact. Despite its age and the lack of known exploits in the wild, the vulnerability remains relevant for legacy systems still running wwwcount 2.3 or similar vulnerable CGI scripts. No official patches are available, so mitigation relies on removing or isolating the vulnerable component or applying custom fixes.

For European organizations, the impact of this vulnerability can be significant if legacy web infrastructure still uses the vulnerable wwwcount 2.3 CGI script. Successful exploitation could lead to unauthorized remote code execution, allowing attackers to take control of web servers, steal sensitive data, modify or delete information, and disrupt services. This could affect confidentiality by exposing sensitive user or organizational data, integrity by allowing unauthorized data modification, and availability by enabling denial-of-service conditions or server takeover. Given the vulnerability requires no authentication and can be triggered remotely, it poses a high risk to exposed web servers. European organizations in sectors such as government, finance, healthcare, and critical infrastructure that maintain legacy web applications or have not updated their web analytics tools may be particularly vulnerable. The lack of patches increases the risk, as organizations must rely on compensating controls. Additionally, compliance with European data protection regulations (e.g., GDPR) could be jeopardized if data breaches occur due to exploitation of this vulnerability.

Since no official patch is available for CVE-1999-0021, European organizations should take the following specific measures: 1) Identify and inventory all instances of wwwcount 2.3 or similar vulnerable CGI scripts within their web infrastructure. 2) Immediately disable or remove the Count.cgi script from production environments to eliminate the attack surface. 3) If the functionality of wwwcount is required, replace it with modern, actively maintained web analytics tools that do not have known vulnerabilities. 4) Implement strict network segmentation and firewall rules to restrict access to legacy web servers, limiting exposure to the internet. 5) Employ web application firewalls (WAFs) with custom rules to detect and block exploit attempts targeting Count.cgi buffer overflow patterns. 6) Conduct regular security assessments and penetration testing focused on legacy systems. 7) Monitor logs and network traffic for unusual command execution patterns or suspicious activity related to CGI scripts. 8) Educate IT staff about the risks of running outdated CGI programs and the importance of timely software updates and decommissioning legacy components.