CVE-2020-13817

Name of the Vulnerable Software and Affected Versions ntp versions 4.2.8 through 4.2.8p14 ntp versions 4.3.x through 4.3.100

Description The issue is related to the implementation of the NTP protocol, specifically with the use of insufficiently random values. This allows a remote attacker to cause a denial of service, either by exiting the daemon or changing the system time, by predicting transmit timestamps for use in spoofed packets. The victim must be relying on unauthenticated IPv4 time sources, and there must be an off-path attacker who can query time from the victim's ntpd instance.

Recommendations For ntp versions 4.2.8 through 4.2.8p14, update to version 4.2.8p15 or later to resolve the issue. For ntp versions 4.3.x through 4.3.100, update to version 4.3.101 or later to resolve the issue. As a temporary workaround, consider restricting access to unauthenticated IPv4 time sources to minimize the risk of exploitation.