NTP BUG 3045: Bad authentication demobilizes ephemeral associations
Last update: April 22, 2024 18:49 UTC (7e7bd5857)
Summary
Description
An attacker who knows the origin timestamp and can send a spoofed packet containing a CRYPTO-NAK
to an ephemeral peer target before any other response is sent can demobilize that association.
Mitigation
- Implement BCP-38.
- Upgrade to 4.2.8p8 or later.
- Properly monitor your
ntpd
instances, and auto-restart ntpd
(without -g
) if it stops running.
Credit
This weakness was discovered by Miroslav Lichvar of Red Hat.
Timeline