virt-v2v before 0.8.4 does not preserve the VNC console password when converting a guest, which allows local users to bypass the intended VNC authentication by connecting without a password.
https://git.fedorahosted.org/cgit/virt-v2v.git/commit/?id=7e9393129116699d1228bb02b9f65b78584582c1
https://euvd.enisa.europa.eu/vulnerability/EUVD-2011-1771
https://bugzilla.redhat.com/show_bug.cgi?id=702754