NTP users are strongly urged to take immediate action to ensure that their NTP daemons are not susceptible to being used in distributed denial-of-service (DDoS) attacks. Please also take this opportunity to defeat denial-of-service attacks by implementing Ingress and Egress filtering through BCP38.

ntp-4.2.8p15 was released on 23 June 2020. It addresses 1 medium-severity security issue in ntpd, and provides 13 non-security bugfixes over 4.2.8p13.

Please see the NTP Security Notice for vulnerability and mitigation details.

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Are you using Autokey in production? If so, please contact Harlan - he's got some questions for you.

Configuration and Authorization Levels for ntpd

Background and History

Analysis

BrianUtterback suggests we need to classify operations on data types as follows:

• public-read-only
• private-read-only
• safe-write
• unsafe-write

Proposals

In the context of prior discussions, safe-write would be any ntpq/ntpdc operation that changes the ntpd state, such as ntpq -c ":config tos minsane 3" except those segregated as particularly dangerous, risking not just timekeeping but the system on which it runs, including:

ntpq -c "saveconfig /path/to/overwrite"
ntpq -c ":config logfile /path/to/appendfile"
ntpq -c ":config enable stats"
ntpq -c ":config filegen ..."

-- DaveHart - 16 Sep 2009