CVE-2000-1164 in WinVNC
Summary
by MITRE
WinVNC installs the WinVNC3 registry key with permissions that give Special Access (read and modify) to the Everybody group, which allows users to read and modify sensitive information such as passwords and gain access to the system.
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Analysis
by VulDB Data Team • 10/11/2025
The vulnerability described in CVE-2000-1164 represents a critical privilege escalation flaw in the WinVNC remote desktop software version 3. This issue stems from improper access control implementation during the software installation process where the WinVNC3 registry key is created with excessively permissive permissions. The registry key is configured to grant Special Access rights including both read and modify permissions to the Everyone group, a default Windows security principal that includes all users on the system regardless of their authentication status or privileges. This misconfiguration creates a fundamental security weakness that directly violates the principle of least privilege and provides unauthorized users with direct access to sensitive system configuration data.
From a technical perspective, the vulnerability manifests through the Windows registry security model where the WinVNC3 registry key is created without proper discretionary access control lists. The Everyone group typically has minimal permissions by default, but in this specific case, the installation process explicitly grants read and modify access to this group. This allows any local user to access the registry entry containing sensitive configuration data, including authentication credentials, encryption keys, and other system access parameters that are typically protected from casual inspection. The vulnerability specifically impacts the Windows registry security mechanism and represents a classic case of insecure default permissions that undermines the security boundaries of the operating system.
The operational impact of this vulnerability is significant as it enables local privilege escalation attacks where any user on the system can potentially access sensitive information and modify system configuration. An attacker with local access can exploit this weakness to extract stored passwords, modify authentication parameters, and potentially gain deeper system access. This vulnerability creates a persistent security risk that remains active as long as the vulnerable WinVNC3 software remains installed on the system. The impact extends beyond simple information disclosure as it can lead to complete system compromise when combined with other attack vectors, making it particularly dangerous in multi-user environments where unauthorized users may gain access to legitimate accounts.
Security professionals should note that this vulnerability aligns with CWE-276, which describes improper permissions for a resource, and represents a clear violation of security best practices for access control management. The ATT&CK framework would categorize this under privilege escalation techniques where adversaries leverage insecure permissions to gain elevated access to system resources. The vulnerability demonstrates how improper installation procedures can create persistent security weaknesses that remain undetected for extended periods. Mitigation strategies should include immediate removal of the vulnerable WinVNC3 software, manual verification of registry permissions, and implementation of proper access control policies. Organizations should also consider implementing registry monitoring tools and regular security audits to detect similar misconfigurations in other software installations. The incident underscores the importance of proper access control implementation during software deployment and highlights the need for security awareness in system administration practices to prevent such vulnerabilities from being introduced into production environments.