CVE-2019-11686 in SanDisk X300
Summary
by MITRE
Western Digital SanDisk X300, X300s, X400, and X600 devices: A vulnerability in the wear-leveling algorithm of the drive may cause cryptographically sensitive parameters (such as data encryption keys) to remain on the drive media after their intended erasure.
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Analysis
by VulDB Data Team • 04/11/2024
The vulnerability identified as CVE-2019-11686 affects Western Digital SanDisk X300, X300s, X400, and X600 solid state drives where the wear-leveling algorithm implementation contains a critical flaw in how it handles data erasure operations. This weakness directly impacts the secure deletion of cryptographically sensitive information, creating potential security risks for users who store confidential data on these devices. The flaw stems from improper handling of data relocation during the wear-leveling process, which is a fundamental mechanism in flash-based storage systems designed to distribute write operations evenly across the memory cells to maximize drive lifespan.
The technical root cause of this vulnerability lies in the inadequate implementation of the wear-leveling algorithm's data management procedures, specifically in how it handles the physical erasure of data blocks. When the system performs wear-leveling operations, it relocates data from one physical location to another to prevent premature cell wear. However, the flaw allows for cryptographic parameters such as encryption keys to persist in residual locations on the storage media even after the system believes these values have been properly erased. This behavior violates fundamental security principles and creates a persistent threat vector where sensitive information could be recovered through forensic analysis techniques. The vulnerability aligns with CWE-254, which addresses security weaknesses related to improper handling of sensitive data, and represents a critical failure in the storage device's data sanitization process.
The operational impact of this vulnerability extends beyond simple data retention concerns, as it fundamentally compromises the security assurances that users expect from enterprise and consumer storage solutions. Organizations relying on these drives for sensitive data storage face potential exposure of encryption keys, cryptographic parameters, and potentially other confidential information that may have been stored in the areas where wear-leveling operations occurred. The risk is particularly significant for environments where data sanitization is critical, such as government agencies, financial institutions, and healthcare organizations handling regulated information. Attackers could potentially exploit this vulnerability through forensic analysis techniques to recover previously deleted encryption keys, undermining the entire encryption framework that protects the stored data. This vulnerability directly impacts the principles outlined in the NIST SP 800-88 standard for media sanitization and could be categorized under ATT&CK technique T1486, which involves data encryption for ransom.
Mitigation strategies for this vulnerability require a multi-layered approach combining immediate device replacement or firmware updates where available, along with enhanced data sanitization protocols. Organizations should implement additional encryption layers and regular data sanitization procedures that go beyond the native drive capabilities, ensuring that critical cryptographic parameters are handled through secure key management systems rather than relying solely on drive-level erasure mechanisms. The recommended approach includes deploying drive-level sanitization tools that perform multiple overwrites and verify complete data destruction, implementing secure key rotation practices, and establishing monitoring protocols to detect potential unauthorized access attempts. Additionally, system administrators should consider implementing storage encryption with independent key management systems that maintain cryptographic separation from the vulnerable storage device's native erasure mechanisms. The vulnerability underscores the importance of comprehensive security testing for storage device firmware and highlights the need for vendors to implement robust data sanitization procedures that meet industry standards including those defined in the ISO/IEC 27001 information security framework.