Microsoft Windows Server 2025
Windows Server 2025 must prevent NTLM from falling back to a Null session
STIG ID:
WN25-SO-000270
|
SRG:
SRG-OS-000480-GPOS-00227
|
Severity:
Medium
|
CCI:
CCI-000366
|
Vulnerability ID:
V-278221
Description
NTLM sessions that are allowed to fall back to Null (unauthenticated) sessions may gain unauthorized access.
Check
C-82751r1181367_chk
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\MSV1_0\
Value Name: allownullsessionfallback
Type: REG_DWORD
Value: 0x00000000 (0)
Fix
F-82656r1181368_fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> Network security: Allow LocalSystem NULL session fallback to "Disabled".