Does this vulnerability mean that a user could change the registry values that specify RASMANs parameters?
Not directly. Keep in mind that registry entries are objects, and have their own permissions. The permissions on RASMAN’s registry entries are correct, and would not allow a normal user to change them. However, because of the inappropriate DACL in RASMAN’s security descriptor, a malicious user could achieve the same effect by using the Service Control Manager to change the RASMAN parameters.