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Self-Encrypting Drives Have Multiple Vulnerabilities

Vulnerability Note VU#395981

Original Release Date: 2018-11-06 | Last Revised: 2018-11-07

Overview

There are multiple vulnerabilities in implementations of ATA Security or TCG Opal Standards in Self-Encrypting Disks (SEDs), which can allow an attacker to decrypt contents of an encrypted drive.

Description

CVE-2018-12037

There is no cryptographic relation between the password provided by the end user and the key used for the encryption of user data. This can allow an attacker to access the key without knowing the password provided by the end user, allowing the attacker to decrypt information encrypted with that key.

According to National Cyber Security Centre - The Netherlands (NCSC-NL), the following products are affected by CVE-2018-12037:

  • Crucial (Micron) MX100, MX200 and MX300 drives
  • Samsung T3 and T5 portable drives
  • Samsung 840 EVO and 850 EVO drives (In "ATA high" mode these devices are vulnerable, In "TCG" or "ATA max" mode these devices are NOT vulnerable.)

    CVE-2018-12038
    Key information is stored within a wear-leveled storage chip. Wear-leveling does not guarantee that an old copy of updated data is fully removed. If the updated data is written to a new segment, old versions of data may exist in the previous segment for some time after it has been updated (until that previous segment is overwritten). This means that if a key is updated with a new password, the previous version of the key (either unprotected, or with an old password) could be accessible, negating the need to know the updated password.

    According to NCSC-NL, the following products are affected by CVE-2018-12038:
  • Samsung 840 EVO drives

    Other products were not reported to have been tested, and similar vulnerabilities may be found in those products.
  • Impact

    These vulnerabilities allow for full recovery of the data without knowledge of any secret, when the attacker has physical access to the drive.

    Solution

    Apply patches
    Vendors have issued patches to address the vulnerabilities. See the Vendor pages below for additional information.

    If patches are not able to be deployed, consider the following workarounds:

    Do not use drive-based encryption
    Use software-based encryption rather than the hardware-based encryption provided by self-encrypting drives.


    Additional Information:
    According to NCSC-NL, BitLocker as bundled with Microsoft Windows relies on hardware full-disk encryption by default if the drive indicates that it can support this.

    To determine whether BitLocker is using hardware-based encryption or software-based encryption:

  • Run "manage-bde.exe -status" in an administrator command prompt.
  • If the "Encryption Method" starts with "Hardware Encryption", then BitLocker is using the self-encrypting disk's hardware-based encryption implementation.
  • If the "Encryption Method" states something other than "Hardware Encryption", such as "AES-128" or "XTS AES-256", then BitLocker is using software-based encryption.

    BitLocker's default encryption method can be controlled with Group Policy settings. Configure these settings to force BitLocker to use software-based encryption by default. Once these policy settings have been changed, BitLocker needs to be disabled and re-enabled to re-encrypt the drive with software-based encryption (if not already using software-based encryption).


    Group policy links to control hardware-based BitLocker encryption:

  • Fixed data drives: https://docs.microsoft.com/en-us/windows/security/information-protection/bitlocker/bitlocker-group-policy-settings#bkmk-hdefxd
  • OS drives: https://docs.microsoft.com/en-us/windows/security/information-protection/bitlocker/bitlocker-group-policy-settings#bkmk-hdeosd
  • Removable drives: https://docs.microsoft.com/en-us/windows/security/information-protection/bitlocker/bitlocker-group-policy-settings#bkmk-hderdd
  • Vendor Information

    395981
    Expand all

    Micron

    Updated:  November 06, 2018

    Status

      Affected

    Vendor Statement

    No statement is currently available from the vendor regarding this vulnerability.

    Vendor Information

    We are not aware of further vendor information regarding this vulnerability.

    Vendor References

    http://www.crucial.com/usa/en/support-ssd-firmware

    Addendum

    There are no additional comments at this time.

    If you have feedback, comments, or additional information about this vulnerability, please send us email.

    Microsoft

    Updated:  November 07, 2018

    Status

      Affected

    Vendor Statement

    Encryption with BitLocker depends on the correct setting of the Group Policy. More information about this Group Policy can be found via the following location (Microsoft URL). Changing the default setting is not sufficient to mitigate the risk because it does not affect the vulnerability in already encrypted data. Only a complete new installation, including removal and reformatting of data, enforces encryption via BitLocker.

    Vendor Information

    For details, please see the vendor's web page.

    Vendor References

    https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/ADV18002 8 https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-s erver-2012-R2-and-2012/jj679890(v=ws.11)#configure-use-of-hardware-based-en cryption-for-fixed-data-drives

    Addendum

    There are no additional comments at this time.

    If you have feedback, comments, or additional information about this vulnerability, please send us email.

    Samsung Memory

    Updated:  November 05, 2018

    Status

      Affected

    Vendor Statement

    For non-portable SSDs: We recommend installing encryption software (freeware available online) that is compatible with your system.

      For portable SSDs: We recommend updating the firmware on your device.

    Vendor Information

    For details please see the Vendor's web page.

    Vendor References

    https://www.samsung.com/semiconductor/minisite/ssd/support/consumer-notice/


    CVSS Metrics

    Group Score Vector
    Base 6.3 AV:L/AC:M/Au:N/C:C/I:C/A:N
    Temporal 4.9 E:POC/RL:OF/RC:C
    Environmental 3.7 CDP:N/TD:M/CR:ND/IR:ND/AR:ND

    References

    Credit

    Thanks to Carlo Meijer and Bernard van Gastel for reporting these vulnerabilities and the National Cyber Security Centre of the Netherlands for leading the coordination of this vulnerability.

    This document was written by Trent Novelly and Laurie Tyzenhaus.

    Other Information

    CVE IDs: CVE-2018-12037 , CVE-2018-12038
    Date Public: 2018-11-05
    Date First Published: 2018-11-06
    Date Last Updated: 2018-11-07 19:43 UTC
    Document Revision: 49

    Sponsored by the Department of Homeland Security Office of Cybersecurity and Communications.