Summary

Disabling UPnP in the GUI

Either

  • turn off the checkbox in the GUI under Options → Network → Map port using UPNP (see above)
  • add the line upnp=0 to your bitcoinv.conf file
  • add -upnp=0 to the command line options

Also upgrade to a version of BitcoinV Core at least 0.10.3 or 0.11.1. These versions upgrade the library to a non-vulnerable version, as well as disable UPnP by default to prevent this problem in the future.