Disable this policy setting to prevent the SMB redirector from sending plaintext passwords during authentication to third-party SMB servers that do not support password encryption. Microsoft recommends that you disable this policy setting unless there is a strong business case to enable it. If this policy setting is enabled, unencrypted passwords will be allowed across the network. Vulnerability: If you enable this policy setting, the server can transmit passwords in plaintext across the network to other computers that offer SMB services. These other computers may not use any of the SMB security mechanisms that are included with Windows Server 2003. Counter Measure: Configure the Microsoft network client: Send unencrypted password to connect to third-party SMB servers setting to Disabled. Potential Impact: Some very old applications and operating systems such as MS-DOS, Windows for Workgroups 3.11, and Windows 95a may not be able to communicate with the servers in your organization by means of the SMB protocol. Fix: (1) GPO: Computer ConfigurationWindows SettingsSecurity SettingsLocal PoliciesSecurity OptionsMicrosoft network client: Send unencrypted password to third-party SMB servers (2) REG: HKEY_LOCAL_MACHINESystemCurrentControlSetServicesLanmanWorkstationParameters!EnablePlainTextPassword

[enable/disable]

(1) GPO: Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options\Microsoft network client: Send unencrypted password to third-party SMB servers (2) REG: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanmanWorkstation\Parameters!EnablePlainTextPassword