CVE-2000-0487 in Windows
Summary
by MITRE
The Protected Store in Windows 2000 does not properly select the strongest encryption when available, which causes it to use a default of 40-bit encryption instead of 56-bit DES encryption, aka the "Protected Store Key Length" vulnerability.
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Analysis
by VulDB Data Team • 04/21/2026
The Protected Store in Windows 2000 represents a critical cryptographic component designed to safeguard sensitive information including passwords and encryption keys. This subsystem operates as a secure repository within the operating system that manages cryptographic credentials and maintains them in an encrypted format. The vulnerability arises from the implementation flaw in how the Protected Store handles encryption algorithm selection during the key management process. When the system attempts to establish secure storage for cryptographic materials, it fails to properly evaluate and select the strongest available encryption algorithm. Instead of leveraging the more robust 56-bit DES encryption that may be available, the system defaults to using 40-bit encryption which significantly weakens the overall security posture. This behavior constitutes a fundamental failure in cryptographic implementation that directly impacts the confidentiality and integrity of stored sensitive data.
The technical flaw manifests as a weakness in the Protected Store's cryptographic selection logic where it does not perform proper algorithm strength evaluation. According to CWE-327, this vulnerability represents a use of a broken or weak cryptographic algorithm, specifically involving the improper selection of encryption key lengths. The system's decision-making process for encryption strength selection appears to prioritize simplicity over security, defaulting to the weakest supported algorithm rather than implementing proper cryptographic best practices. This weakness creates a predictable security gap where attackers can potentially exploit the reduced encryption strength to compromise stored credentials and sensitive information. The 40-bit encryption key length provides insufficient entropy to withstand modern cryptanalytic attacks, making the stored data vulnerable to brute force and other cryptographic attacks. The vulnerability essentially undermines the intended security model of the Protected Store by introducing a predictable weakness in the encryption implementation.
The operational impact of this vulnerability extends beyond simple cryptographic weakness to encompass broader system security implications. When the Protected Store employs 40-bit encryption instead of the available 56-bit DES, it creates a significant security gap that affects all applications and services relying on this storage mechanism. This weakness particularly impacts systems where sensitive authentication data, encryption keys, and other cryptographic materials are stored in the Protected Store. The vulnerability affects the overall trust model of Windows 2000 systems and can enable attackers to compromise user credentials, session keys, and other sensitive information. From an attacker's perspective, this vulnerability aligns with techniques described in the ATT&CK framework under credential access and defense evasion tactics, as it provides a pathway to extract and potentially manipulate stored cryptographic materials. The reduced encryption strength means that attackers with sufficient computational resources can more easily break the encryption and access protected information, undermining the fundamental security assumptions of the operating system's credential management.
Mitigation strategies for this vulnerability require both immediate and long-term approaches to address the cryptographic weakness in the Protected Store implementation. System administrators should consider upgrading to newer operating systems where this vulnerability has been addressed through improved cryptographic implementation and stronger default encryption settings. The immediate remediation involves ensuring that systems are not relying on the vulnerable Protected Store functionality where possible, and implementing additional layers of security through network segmentation and access controls. Security patches and updates should be applied to address the underlying implementation flaw, though in many cases the vulnerability may require a complete system upgrade to ensure proper cryptographic implementation. Organizations should also implement monitoring and detection capabilities to identify potential exploitation attempts targeting the Protected Store functionality, as this vulnerability may be targeted by attackers seeking to compromise stored credentials and cryptographic materials. The vulnerability highlights the importance of proper cryptographic algorithm selection and implementation practices that align with industry standards and security best practices.