Oracle Linux: CVE-2020-13817: ELSA-2020-2663: ntp security update (MODERATE) (Multiple Advisories)

Description

ntpd in ntp before 4.2.8p14 and 4.3.x before 4.3.100 allows remote attackers to cause a denial of service (daemon exit or system time change) by predicting transmit timestamps for use in spoofed packets. The victim must be relying on unauthenticated IPv4 time sources. There must be an off-path attacker who can query time from the victim's ntpd instance. A high-performance ntpd instance that gets its time from unauthenticated IPv4 time sources may be vulnerable to an off-path attacker who can query time from the victim's ntpd instance. An attacker who can send a large number of packets with the spoofed IPv4 address of the upstream server can use this flaw to modify the victim's clock by a limited amount or cause ntpd to exit.