The read_from_cmd_socket function in cmdmon.c in chronyd in Chrony before 1.23.1, and 1.24-pre1, allows remote attackers to cause a denial of service (CPU and bandwidth consumption) by sending a spoofed cmdmon packet that triggers a continuous exchange of NOHOSTACCESS messages between two daemons, a related issue to CVE-2009-3563.

ntp_request.c in ntpd in NTP before 4.2.4p8, and 4.2.5, allows remote attackers to cause a denial of service (CPU and bandwidth consumption) by using MODE_PRIVATE to send a spoofed (1) request or (2) response packet that triggers a continuous exchange of MODE_PRIVATE error responses between two NTP daemons.