Actually I cant see why this parse call is even needed in this code. Its only being used as a validator.
As for the the alternative being to disable tls, thats not the case. If (vulnversion) { die() } is also a valid way to handle this -- lets not continue to be a slave to sacrificing security to bad sysadmins who refuse to patch in the name of compatibility. 

As detailed below, this could result in privilege escalation attacks and other nastiness.