Title

Terminal Services is not configured to limit the number of connections. (Cat II impact)

Discussion

This setting limits the number of simultaneous connections allowed to the terminal server. By default, unlimited connections are allowed. Allowing unlimited connections allows a potential DoS attack. The number of incoming connections should be limited to one.

Check Content

If the following registry value doesn’t exist or its value is not set to 1, then this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Subkey: \Software\Policies\Microsoft\Windows NT\Terminal Services\ Value Name: MaxInstanceCount Type: REG_DWORD Value: 1 Documentable Explanation: If the system has the role as a Terminal Server, or the site is using terminal services for remote administration this requirement needs to be documented with the IAO.

Fix Text

Configure the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Terminal Services “Limit Number of Connections” to “Enabled”, and the value “TS maximum connections allowed” to no more than “1”.

Additional Identifiers

Rule ID: SV-3450r2_rule

Vulnerability ID: V-3450

Group Title:

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.