CVE-2015-1799: Ntp

Medium severity, CVSS 4.3. EPSS: 0.9% chance of exploitation in the next 30 days.

The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP 3.x and 4.x before 4.2.8p2 performs state-variable updates upon receiving certain invalid packets, which makes it easier for man-in-the-middle attackers to cause a denial of service (synchronization loss) by spoofing the source IP address of a peer.

Affected products

• Ntp Ntp: up to and including 4.2.7p444

Published 2015-04-08. Last modified 2026-06-17.