The PPP parser in tcpdump before 4.9.2 has a buffer over-read in print-ppp.c:print_ccp_config_options().
https://support.apple.com/HT208221
https://security.gentoo.org/glsa/201709-23
https://github.com/the-tcpdump-group/tcpdump/commit/7029d15f148ef24bb7c6668bc640f5470d085e5a
https://access.redhat.com/errata/RHEA-2018:0705
http://www.tcpdump.org/tcpdump-changes.txt