CVE-2025-59320 in Secure Disk for BitLocker
Summary
by MITRE • 08/12/2026
CPSD CryptoPro Secure Disk for Bitlocker before v7.7.4 stores TPM2.0 secrets in a serialized format within unused disk sectors. An unauthenticated attacker with physical access to the system disk can recover this information and craft an environment to unseal the TPM.
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Analysis
by VulDB Data Team • 08/12/2026
This vulnerability resides in the CryptoPro Secure Disk for BitLocker implementation prior to version 7.7.4, where the software incorrectly handles TPM 2.0 secret storage by persisting these sensitive cryptographic materials in serialized format within unused disk sectors. The flaw represents a critical security oversight that directly violates established principles of secure key management and demonstrates poor adherence to cryptographic best practices. When BitLocker encryption is enabled with CryptoPro Secure Disk, the system generates and stores TPM 2.0 secrets in a predictable location on the disk, specifically within sectors that are not actively used for storage purposes. This approach creates an attack surface where physical access to the system disk becomes sufficient to extract confidential information through simple forensic analysis techniques.
The technical exploitation of this vulnerability occurs when an unauthenticated attacker gains physical access to the target system and can read the raw disk contents. The serialized TPM 2.0 secrets stored in unused sectors contain the cryptographic keys necessary to decrypt BitLocker-protected volumes, allowing attackers to construct a proper environment for unsealing these secrets without requiring authentication or knowledge of user credentials. This attack vector specifically aligns with the ATT&CK technique T1499.001 which covers "Storage Occupancy" and represents a form of credential access through physical system compromise. The vulnerability can be categorized under CWE-310 as "Cryptographic Issues" and more specifically relates to CWE-327 which addresses "Use of a Broken or Risky Cryptographic Algorithm" in the context of improper key storage mechanisms.
The operational impact of this vulnerability extends beyond simple data theft, as it fundamentally undermines the security model that BitLocker relies upon for protecting encrypted volumes. An attacker who successfully extracts these TPM secrets can not only decrypt the protected disk but potentially gain access to additional systems or networks where similar encryption schemes have been implemented. This creates a cascading risk where compromising one system with this vulnerability can lead to broader network infiltration. The flaw particularly affects enterprise environments where physical security controls may be insufficient, as it demonstrates that even systems with strong logical authentication mechanisms can be compromised through physical access attacks. Organizations relying on CryptoPro Secure Disk for BitLocker without proper mitigation measures face significant risks of data breaches and unauthorized access to sensitive information.
Mitigation strategies for this vulnerability require immediate implementation of version 7.7.4 or later, which addresses the insecure storage mechanism by properly encrypting TPM secrets before persistence. System administrators should also implement additional physical security controls such as disk encryption with strong authentication mechanisms, proper system hardening, and monitoring for unauthorized physical access to systems. Organizations must conduct thorough risk assessments to identify all affected systems and ensure proper key management practices are implemented. The vulnerability highlights the importance of following established cryptographic standards and principles, particularly those outlined in NIST SP 800-57 for key management and the recommendations from ISO/IEC 14443 for secure data handling. Regular security audits and penetration testing should be conducted to identify similar storage patterns that might expose other cryptographic materials, ensuring comprehensive protection against both logical and physical attack vectors.