tinc 1.0.30 through 1.0.34 has a broken authentication protocol, although there is a partial mitigation. This is fixed in 1.1.
https://www.starwindsoftware.com/security/sw-20190227-0002/
https://www.debian.org/security/2018/dsa-4312
http://www.tinc-vpn.org/git/browse?p=tinc%3Ba=commit%3Bh=d3297fbd3b8c8c8a4661f5bbf89aca5cacba8b5a