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.Are you using Autokey in production? If so, please contact Harlan - he's got some questions for you.
ctl_put()
functions (Medium) ntpd
makes use of different wrappers around ctl_putdata()
to create name/value ntpq
(mode 6) response strings. For example, ctl_putstr()
is usually used to send string data (variable names or string data). The formatting code was missing a length check for variable names. If somebody explicitly created any unusually long variable names in ntpd
(longer than 200-512 bytes, depending on the type of variable), then if any of these variables are added to the response list it would overflow a buffer.
setvar
variable names longer than 200-512 bytes in your ntp.conf
file.
ntpd
instances, and auto-restart ntpd
(without -g
) if it stops running.