Title

Windows 11 systems must use a BitLocker PIN with a minimum length of six digits for pre-boot authentication. (Cat II impact)

Discussion

If data at rest is unencrypted, it is vulnerable to disclosure. Even if the operating system enforces permissions on data access, an adversary can remove non-volatile memory and read it directly, thereby circumventing operating system controls. Encrypting the data ensures that confidentiality is protected even when the operating system is not running. Pre-boot authentication prevents unauthorized users from accessing encrypted drives. Increasing the pin length requires a greater number of guesses for an attacker.

Check Content

If the following registry value does not exist or is not configured as specified, this is a finding: For virtual desktop implementations (VDIs) in which the virtual desktop instance is deleted or refreshed upon logoff, this is NA. For AVD implementations with no data at rest, this is NA. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\FVE\ Value Name: MinimumPIN Type: REG_DWORD Value: 0x00000006 (6) or greater

Fix Text

Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> BitLocker Drive Encryption >> Operating System Drives "Configure minimum PIN length for startup" to "Enabled" with "Minimum characters:" set to "6" or greater.

Additional Identifiers

Rule ID: SV-253261r958504_rule

Vulnerability ID: V-253261

Group Title: SRG-OS-000121-GPOS-00062

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.