CVE-2000-0364 is a vulnerability identified in the screen and rxvt terminal emulator programs included with Red Hat Linux 6.0. The issue arises because these programs do not properly set the modes of tty (teletypewriter) devices. TTY devices represent terminal interfaces in Unix-like operating systems, and their mode settings control permissions and access rights. Improper mode settings in this context allow local users to write to other users' tty devices, effectively enabling them to send unsolicited output or potentially malicious commands to other users' terminal sessions. This vulnerability is local in nature, meaning an attacker must have local access to the system to exploit it. The CVSS score of 4.6 (medium severity) reflects that the attack vector is local, the attack complexity is low, no authentication is required, and the impact affects confidentiality, integrity, and availability to some extent. Although no patches are available and no known exploits have been reported in the wild, the vulnerability poses a risk of information leakage and potential disruption of terminal sessions. Given the age of the vulnerability (published in 1999) and the specific affected version (Red Hat Linux 6.0), this issue is primarily relevant to legacy systems still running this outdated distribution or its derivatives without updates or mitigations.

For European organizations, the impact of this vulnerability is primarily relevant to environments that still operate legacy Red Hat Linux 6.0 systems, which is uncommon in modern enterprise settings. However, in niche industrial, research, or governmental environments where legacy systems persist, exploitation could lead to unauthorized users injecting output or commands into other users' terminal sessions. This could result in information disclosure, user confusion, or disruption of critical terminal-based workflows. The vulnerability compromises confidentiality by allowing data leakage through terminal output, integrity by permitting unauthorized terminal input, and availability by potentially disrupting user sessions. While remote exploitation is not possible, the risk remains for insider threats or attackers who have gained local access through other means. The absence of patches means organizations must rely on compensating controls or system upgrades to mitigate risk. Overall, the threat is limited in scope but could have operational impacts in legacy system contexts within European organizations.

Since no official patches are available for this vulnerability, European organizations should prioritize upgrading from Red Hat Linux 6.0 to a supported and actively maintained Linux distribution version that addresses this and other security issues. For environments where upgrading is not immediately feasible, practical mitigations include restricting local user access to trusted personnel only, implementing strict user account management and monitoring, and using access control mechanisms such as SELinux or AppArmor to limit the ability of users to interact with tty devices they do not own. Additionally, organizations can consider replacing screen and rxvt with alternative terminal emulators that properly handle tty device modes. Regular auditing of tty device permissions and monitoring for unusual terminal activity can help detect exploitation attempts. Finally, network segmentation and limiting physical or remote access to legacy systems reduce the risk of unauthorized local access.