nfdump 1.6.17 and earlier is affected by an integer overflow in the function Process_ipfix_template_withdraw in ipfix.c that can be abused in order to crash the process remotely (denial of service).
https://security.gentoo.org/glsa/202003-17
https://lists.debian.org/debian-lts-announce/2020/09/msg00021.html
https://github.com/phaag/nfdump/issues/171
https://github.com/phaag/nfdump/commit/3b006ededaf351f1723aea6c727c9edd1b1fff9b