CVE-2000-0369 is a vulnerability found in the IDENT server component of Caldera Linux version 2.3, an older Linux distribution. The IDENT server is designed to respond to identification requests on TCP port 113, typically used to identify the user of a particular TCP connection. In this specific vulnerability, the IDENT server creates multiple threads for each incoming IDENT request without proper limits or controls. This behavior can be exploited by a remote attacker who sends a large number of IDENT requests, causing the server to spawn excessive threads. The uncontrolled thread creation leads to resource exhaustion, resulting in a denial of service (DoS) condition where legitimate users cannot access the IDENT service or potentially other services on the affected system. The vulnerability does not affect confidentiality or integrity but impacts availability. The CVSS score is 5.0 (medium severity), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no authentication required (Au:N), no impact on confidentiality or integrity (C:N/I:N), and partial impact on availability (A:P). There is no patch available for this vulnerability, and no known exploits have been reported in the wild. Given the age of the product and the vulnerability, modern systems are unlikely to be affected, but legacy systems running Caldera Linux 2.3 with the IDENT server enabled remain at risk.

For European organizations, the impact of this vulnerability is primarily a denial of service risk on systems running Caldera Linux 2.3 with the IDENT server enabled. While Caldera Linux is an outdated distribution with very limited use today, some legacy industrial, research, or governmental systems might still operate such environments. A successful DoS attack could disrupt network identification services, potentially affecting logging, auditing, or access control mechanisms that rely on IDENT responses. This could lead to operational disruptions or complicate incident response efforts. However, the overall risk is limited due to the obsolescence of the affected software and the lack of known active exploitation. Organizations relying on legacy systems should be aware of this vulnerability as part of their risk assessments and incident response planning.

Since no patch is available, mitigation must focus on reducing exposure and limiting the impact. Specific recommendations include: 1) Disable the IDENT server if it is not required, as IDENT is rarely essential in modern environments. 2) If IDENT service is necessary, implement network-level controls such as firewall rules to restrict access to TCP port 113 only to trusted hosts or internal networks, thereby reducing the attack surface. 3) Employ rate limiting or connection throttling on the IDENT service to prevent excessive thread creation from rapid or numerous requests. 4) Monitor network traffic and system resource usage for unusual spikes that may indicate exploitation attempts. 5) Consider migrating legacy systems to supported and updated operating systems to eliminate exposure to this and other legacy vulnerabilities.