Windows Server 2025 insecure logons to an SMB server must be disabled.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-278086 | WN25-CC-000070 | SV-278086r1180964_rule | CCI-000366 | medium |
| Description | ||||
| Insecure guest logons allow unauthenticated access to shared folders. Shared resources on a system must require authentication to establish proper access. | ||||
| STIG | Date | |||
| Microsoft Windows Server 2025 Security Technical Implementation Guide | 2026-02-20 | |||
Details
Check Text (C-278086r1180964_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: \SOFTWARE\Policies\Microsoft\Windows\LanmanWorkstation\
Value Name: AllowInsecureGuestAuth
Type: REG_DWORD
Value: 0x00000000 (0)
Fix Text (F-82521r1180963_fix)
Configure the policy value for Computer Configuration >> Administrative Templates >> Network >> Lanman Workstation >> Enable insecure guest logons to "Disabled".