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

STIG ID: WN10-SO-000190 |  SRG: SRG-OS-000120-GPOS-00061 |  Severity: medium |  CCI:  | Vulnerability Id: V-220936

Vulnerability Discussion

Certain encryption types are no longer considered secure. This setting configures a minimum encryption type for Kerberos, preventing the use of the DES and RC4 encryption suites.

Check

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

Fix

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)