CVE-1999-0262 is a high-severity remote code execution vulnerability affecting the faxsurvey CGI script component of the Hylafax fax server software on Linux systems. The vulnerability arises because the faxsurvey script improperly handles shell metacharacters embedded in the query string of HTTP requests. This improper input validation allows an unauthenticated remote attacker to inject arbitrary shell commands that the server executes with the privileges of the web server process. The vulnerability is exploitable over the network without any authentication or user interaction, making it a critical risk for exposed systems. The faxsurvey CGI script is designed to collect survey data related to fax transmissions, but its legacy code does not sanitize input parameters, leading to command injection. The CVSS v2 score of 7.5 reflects the high impact on confidentiality, integrity, and availability, as an attacker can execute arbitrary commands, potentially leading to full system compromise. No patches or fixes are available, and there are no known exploits in the wild documented, likely due to the age of the vulnerability and the declining use of Hylafax in modern environments. However, any remaining deployments of Hylafax with the vulnerable faxsurvey script remain at risk if exposed to untrusted networks.

For European organizations, the impact of this vulnerability depends on the presence of legacy Hylafax fax servers running the vulnerable faxsurvey CGI script. Organizations in sectors such as government, healthcare, legal, and manufacturing that historically relied on fax communications may still have legacy systems in place. Exploitation could lead to unauthorized disclosure of sensitive information (confidentiality impact), unauthorized modification or deletion of data (integrity impact), and disruption of fax services or broader system availability. Since the vulnerability allows remote command execution without authentication, attackers could pivot from compromised fax servers to other internal systems, increasing the risk of lateral movement and broader network compromise. Although modern fax usage has declined, some European organizations still rely on fax for regulatory or operational reasons, making this vulnerability relevant. The lack of patches means organizations must rely on compensating controls to mitigate risk.

Given the absence of official patches, European organizations should take the following specific measures: 1) Identify and inventory all Hylafax installations, particularly those exposing the faxsurvey CGI script to untrusted networks. 2) Immediately restrict network access to faxsurvey CGI endpoints using network segmentation, firewall rules, or web application firewalls (WAFs) to block external HTTP requests targeting the vulnerable script. 3) Disable or remove the faxsurvey CGI script if it is not essential to operations. 4) If faxsurvey functionality is required, consider isolating the fax server in a hardened network segment with strict access controls and monitoring. 5) Implement intrusion detection/prevention systems (IDS/IPS) with signatures to detect suspicious command injection attempts targeting faxsurvey. 6) Monitor logs for unusual HTTP requests containing shell metacharacters or other injection patterns. 7) Plan for migration away from legacy fax infrastructure to modern, secure communication alternatives to eliminate exposure to outdated software vulnerabilities.