Windows Server 2022 Kerberos encryption types must be configured to prevent the use of DES and RC4 encryption suites.

Documentable No

Rule ID SV-254473r971535_rule

CCI References

CCI-000803

Discussion

Certain encryption types are no longer considered secure. The DES and RC4 encryption suites must not be used for Kerberos encryption. Note: Organizations with domain controllers running earlier versions of Windows where RC4 encryption is enabled, selecting "The other domain supports Kerberos AES Encryption" on domain trusts, may be required to allow client communication across the trust relationship.

Check Procedure

If the following registry value does not exist or is not configured as specified, this is a finding:

Registry Hive: HKEY_LOCAL_MACHINE
Registry Path: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters\

Value Name: SupportedEncryptionTypes

Value Type: REG_DWORD
Value: 0x7ffffff8 (2147483640)

Fix Action

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> Network security: Configure encryption types allowed for Kerberos to "Enabled" with only the following selected:

AES128_HMAC_SHA1
AES256_HMAC_SHA1
Future encryption types

Note: Organizations with domain controllers running earlier versions of Windows where RC4 encryption is enabled, selecting "The other domain supports Kerberos AES Encryption" on domain trusts, may be required to allow client communication across the trust relationship.