Windows Server 2019 must be configured to prevent the storage of the LAN Manager hash of passwords.

Documentable No

Rule ID SV-205654r1051063_rule

CCI References

CCI-004062CCI-000196

Discussion

The LAN Manager hash uses a weak encryption algorithm and there are several tools available that use this hash to retrieve account passwords. This setting controls whether a LAN Manager hash of the password is stored in the SAM the next time the password is changed.

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: \SYSTEM\CurrentControlSet\Control\Lsa\

Value Name: NoLMHash

Value Type: REG_DWORD
Value: 0x00000001 (1)

Fix Action

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Do not store LAN Manager hash value on next password change" to "Enabled".