NTP before 4.2.8p7 and 4.3.x before 4.3.92 allows remote attackers to cause a denial of service (prevent subsequent authentication) by leveraging knowledge of the controlkey or requestkey and sending a crafted packet to ntpd, which changes the value of trustedkey, controlkey, or requestkey. NOTE: this vulnerability exists because of a CVE-2016-2516 regression.
Exploitability
AV:NAC:HPR:LUI:NScope
S:UImpact
C:NI:NA:H5.3/CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H