Windows Server 2025 insecure logons to an SMB server must be disabled.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-278086 | SRG-OS-000480-GPOS-00227 | WN25-CC-000070 | SV-278086r1180964_rule | 2026-02-20 | 1 |
Description
Insecure guest logons allow unauthenticated access to shared folders. Shared resources on a system must require authentication to establish proper access.
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: \SOFTWARE\Policies\Microsoft\Windows\LanmanWorkstation\
Value Name: AllowInsecureGuestAuth
Type: REG_DWORD
Value: 0x00000000 (0)
✔️ Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Network >> Lanman Workstation >> Enable insecure guest logons to "Disabled".