The VTP parser in tcpdump before 4.9.2 has a buffer over-read in print-vtp.c:vtp_print().
https://support.apple.com/HT208221
https://security.gentoo.org/glsa/201709-23
https://github.com/the-tcpdump-group/tcpdump/commit/d692d67332bcc90540088ad8e725eb3279e39863
https://github.com/the-tcpdump-group/tcpdump/commit/c5dd7bef5e54da5996dc4713284aa6266ae75b75
https://access.redhat.com/errata/RHEA-2018:0705
http://www.tcpdump.org/tcpdump-changes.txt