In BIND 9.15.6 -> 9.16.5, 9.17.0 -> 9.17.3, An attacker who can establish a TCP connection with the server and send data on that connection can exploit this to trigger the assertion failure, causing the server to exit.
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html
https://kb.isc.org/docs/cve-2020-8620
https://security.gentoo.org/glsa/202008-19