1.234 WN19-SO-000270

Information

Windows Server 2019 must prevent NTLM from falling back to a Null session.

GROUP ID:V-205917
RULE ID:SV-205917r991589

NTLM sessions that are allowed to fall back to Null (unauthenticated) sessions may gain unauthorized access.

Solution

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> 'Network security: Allow LocalSystem NULL session fallback' to 'Disabled'.

See Also

https://workbench.cisecurity.org/benchmarks/22176