CVE-2000-0420 in Windows
Summary
by MITRE
The default configuration of SYSKEY in Windows 2000 stores the startup key in the registry, which could allow an attacker tor ecover it and use it to decrypt Encrypted File System (EFS) data.
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Analysis
by VulDB Data Team • 04/21/2026
The vulnerability described in CVE-2000-0420 represents a critical weakness in the Windows 2000 operating system's implementation of the SYSKEY mechanism, which is designed to protect the Encrypted File System (EFS) functionality. This flaw stems from the default configuration where the system startup key is stored in the Windows registry in an unencrypted format, creating a significant security risk for systems that rely on EFS encryption for data protection. The vulnerability specifically targets the foundational security controls that Microsoft implemented to safeguard encrypted data, thereby undermining the integrity of the entire encryption framework.
The technical implementation of this vulnerability involves the improper storage of cryptographic keys within the Windows registry, which is a well-established system configuration that can be accessed by unauthorized users with sufficient privileges. When Windows 2000 is configured with the default SYSKEY settings, the startup key required to decrypt EFS-protected files is stored in a location that lacks proper access controls, making it susceptible to extraction by attackers who can read the registry entries. This represents a classic case of weak key management where sensitive cryptographic material is stored in a manner that does not adequately protect it from unauthorized access, violating fundamental security principles of key storage and access control.
The operational impact of this vulnerability extends far beyond simple data exposure, as it fundamentally compromises the confidentiality assurances provided by the Encrypted File System. An attacker who successfully recovers the SYSKEY can decrypt any EFS-protected files on the system, potentially gaining access to sensitive documents, personal information, or proprietary data that was intended to remain secure. This vulnerability affects systems that have EFS enabled and configured with the default SYSKEY settings, which was the standard configuration for many Windows 2000 installations, making it a widespread concern across enterprise environments. The implications are particularly severe in corporate environments where sensitive business data, financial records, and personal employee information are commonly encrypted using EFS.
Organizations can mitigate this vulnerability by implementing several remediation strategies that address the root cause of the issue. The primary recommendation involves configuring SYSKEY with a strong, randomly generated key that is not stored in the registry, but rather managed through secure boot processes or hardware security modules. Additionally, administrators should consider disabling EFS encryption on systems where it is not strictly required, or implementing proper access controls and monitoring to detect unauthorized registry access attempts. This vulnerability aligns with CWE-310, which addresses cryptographic issues related to key management, and represents a significant concern from an attacker perspective as outlined in the MITRE ATT&CK framework under the credential access and defense evasion tactics. The vulnerability demonstrates how default configurations can create security weaknesses that persist across multiple systems and environments, emphasizing the importance of security hardening practices and proper configuration management in enterprise security deployments.