The the service does not require you to have a client cert then you are safe. If you are not sure about whether or not you need a client cert for a service the

The the service does not require you to have a client cert then you are safe. If you are not sure about whether or not you need a client cert for a service then you probably don't use one. As mentioned previously, the only commonly used systems that have this vulnerability are SSL VPN setups with the paranoid bit turned on.