CVE-2016-2517

Name of the Vulnerable Software and Affected Versions NTP versions 4.2.8p7 and earlier, 4.3.x before 4.3.92

Description The issue allows remote attackers to cause a denial of service by preventing subsequent authentication. This is achieved by leveraging knowledge of the controlkey or requestkey and sending a crafted packet to ntpd, which changes the value of trustedkey, controlkey, or requestkey. The vulnerability exists due to a regression of a previous issue.

Recommendations For NTP versions 4.2.8p7 and earlier: update to version 4.2.8p7 or later. For NTP versions 4.3.x before 4.3.92: update to version 4.3.92 or later. As a temporary workaround, consider restricting access to the ntpd service to minimize the risk of exploitation.