CVE-2000-0155 is a high-severity vulnerability affecting Microsoft Windows NT 4.0, specifically related to the Autorun feature. The vulnerability arises because Windows NT Autorun executes the autorun.inf file located on non-removable media drives. Normally, autorun.inf files are used on removable media like CDs or USB drives to automatically launch programs. However, in this case, the system improperly processes autorun.inf files on fixed drives, allowing a local attacker to craft an autorun.inf file that specifies an alternate program to execute. When other users access the compromised drive, the specified malicious program is executed automatically without their explicit consent or awareness. This behavior can lead to arbitrary code execution with the privileges of the user accessing the drive. The vulnerability is classified under CWE-94 (Improper Control of Generation of Code), indicating that it allows execution of attacker-controlled code. The CVSS v2 base score is 7.2 (high), with the vector AV:L/AC:L/Au:N/C:C/I:C/A:C, meaning the attack requires local access but no authentication, has low complexity, and impacts confidentiality, integrity, and availability fully. There is no patch available for this vulnerability, and no known exploits have been reported in the wild. The affected product is Windows NT 4.0, an outdated operating system no longer supported by Microsoft. This vulnerability primarily affects legacy systems still running Windows NT 4.0 with Autorun enabled on fixed drives, allowing local attackers to escalate privileges or execute arbitrary code by placing a crafted autorun.inf file on a non-removable drive accessible by other users.

For European organizations, the impact of CVE-2000-0155 is generally limited due to the obsolescence of Windows NT 4.0 in modern IT environments. However, certain legacy industrial control systems, embedded devices, or specialized infrastructure in sectors such as manufacturing, utilities, or government agencies may still run Windows NT 4.0 or similar legacy systems. In such cases, the vulnerability could allow local attackers to execute arbitrary code with user-level privileges, potentially leading to unauthorized access, data compromise, or disruption of critical operations. The full compromise of confidentiality, integrity, and availability is possible if exploited. Since the attack requires local access, the threat vector is primarily insider threats or attackers who have gained initial foothold on the network or physical access to affected machines. The lack of a patch means organizations must rely on compensating controls. The risk is higher in environments where legacy systems are interconnected with modern networks, increasing the potential for lateral movement and broader impact. Overall, while the direct risk to most European organizations is low due to the rarity of Windows NT 4.0 usage, critical infrastructure or legacy-dependent sectors may face moderate risk if mitigation is not applied.

Given the absence of an official patch, European organizations should implement specific mitigations to reduce risk from CVE-2000-0155. First, identify and inventory all systems running Windows NT 4.0 or similar legacy OS versions. For these systems, disable the Autorun feature on all fixed drives via system configuration or group policies to prevent automatic execution of autorun.inf files. Restrict local user permissions to prevent unauthorized creation or modification of autorun.inf files on fixed drives. Implement strict access controls and monitoring on legacy systems to detect unauthorized file changes or suspicious activity. Where possible, isolate legacy systems from the main corporate network using network segmentation or air-gapping to limit attacker movement. Employ endpoint security solutions capable of detecting and blocking execution of unauthorized programs triggered by autorun.inf files. Conduct user awareness training focused on risks of local attacks and the importance of physical security. Finally, plan and prioritize migration away from Windows NT 4.0 to supported operating systems to eliminate exposure to this and other legacy vulnerabilities.