CVE-1999-0913 is a critical remote command execution vulnerability found in the dfire.cgi script of the Dragon-Fire Intrusion Detection System (IDS) version 1.0. The vulnerability arises because the dfire.cgi script improperly handles user input, allowing remote attackers to inject shell metacharacters. This flaw enables attackers to execute arbitrary commands on the underlying operating system with the privileges of the web server process running the CGI script. Since the vulnerability is accessible remotely over the network without any authentication, it poses a severe risk. The attack vector involves sending specially crafted HTTP requests containing shell metacharacters that the script passes unsanitized to the system shell, resulting in command injection. The vulnerability affects the Dragon-Fire IDS product, which was designed to monitor network traffic for suspicious activity. However, the presence of this vulnerability ironically exposes the IDS itself to compromise. The CVSS v2 score of 10.0 (AV:N/AC:L/Au:N/C:C/I:C/A:C) reflects the maximum severity, indicating that exploitation is trivial, requires no authentication, and leads to complete compromise of confidentiality, integrity, and availability of the affected system. No patches or fixes are available, and there are no known exploits in the wild, likely due to the age of the product and vulnerability. Nevertheless, the risk remains for any legacy deployments still running this vulnerable version of Dragon-Fire IDS.

For European organizations, the impact of this vulnerability can be significant if they still use Dragon-Fire IDS version 1.0 in their network security infrastructure. Successful exploitation would allow attackers to gain full control over the IDS host system remotely, potentially leading to data breaches, network reconnaissance, lateral movement, and disruption of security monitoring capabilities. This could result in loss of sensitive data, unauthorized access to internal systems, and degradation or disabling of intrusion detection capabilities, severely weakening the organization's security posture. Given the IDS role in monitoring and alerting on malicious activity, its compromise could allow attackers to operate stealthily within the network. European organizations in critical infrastructure sectors, finance, government, and telecommunications are particularly at risk if they rely on this product. Additionally, the vulnerability’s remote and unauthenticated nature increases the likelihood of exploitation if the system is exposed to untrusted networks.

Since no official patches or updates are available for this vulnerability, European organizations should take immediate compensating controls. First, they should identify and inventory any deployments of Dragon-Fire IDS version 1.0 and isolate these systems from untrusted networks to prevent remote exploitation. If possible, discontinue use of this outdated IDS product and replace it with a modern, actively maintained intrusion detection or prevention system that receives regular security updates. Network segmentation should be employed to limit access to the IDS management interfaces. Additionally, deploying web application firewalls (WAFs) or intrusion prevention systems (IPS) that can detect and block attempts to exploit command injection via CGI scripts can provide a layer of defense. Monitoring network traffic for anomalous requests targeting dfire.cgi or suspicious command injection patterns is also recommended. Finally, organizations should implement strict input validation and sanitization practices in any custom web scripts to prevent similar vulnerabilities.