Windows Server 2019 unencrypted passwords must not be sent to third-party Server Message Block (SMB) servers.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-205655SRG-OS-000074-GPOS-00042WN19-SO-000180SV-205655r987796_rule2025-02-253
Description
Some non-Microsoft SMB servers only support unencrypted (plain-text) password authentication. Sending plain-text passwords across the network when authenticating to an SMB server reduces the overall security of the environment. Check with the vendor of the SMB server to determine if there is a way to support encrypted password authentication.
ℹ️ Check
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\Services\LanmanWorkstation\Parameters\ Value Name: EnablePlainTextPassword Value Type: REG_DWORD Value: 0x00000000 (0)
✔️ Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Microsoft Network Client: Send unencrypted password to third-party SMB servers" to "Disabled".