The recv_and_process_client_pkt function in networking/ntpd.c in busybox allows remote attackers to cause a denial of service (CPU and bandwidth consumption) via a forged NTP packet, which triggers a communication loop.
https://security.gentoo.org/glsa/201701-05
https://seclists.org/bugtraq/2019/Sep/7
https://seclists.org/bugtraq/2019/Jun/14
https://git.busybox.net/busybox/commit/?id=150dc7a2b483b8338a3e185c478b4b23ee884e71
https://bugzilla.redhat.com/show_bug.cgi?id=1363710
http://www.securityfocus.com/bid/92277
http://www.openwall.com/lists/oss-security/2016/08/03/7
http://seclists.org/fulldisclosure/2020/Mar/15
http://seclists.org/fulldisclosure/2020/Aug/20
http://seclists.org/fulldisclosure/2019/Sep/7