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-4.2.8p13
was released on 07 March 2019. It addresses 1 medium-severity security issue in ntpd, and provides 17 non-security bugfixes and 1 other improvements over 4.2.8p12.
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.
ntpq saveconfig
command allows dangerous characters in filenames ntpq
saveconfig
command does not do adequate filtering of special characters from the supplied filename. Note well: The ability to use the saveconfig
command is controlled by the restrict nomodify
directive, and the recommended default configuration is to disable this capability. If the ability to execute a saveconfig
is required, it can easily (and should) be limited and restricted to a known small number of IP addresses.
restrict default nomodify
in your ntp.conf
file.
configure --disable-saveconfig
if you will never need this capability, or
restrict default nomodify
in your ntp.conf
file. Be careful about what IPs have the ability to send modify
requests to ntpd
.
ntpd
instances.
saveconfig
requests are logged to syslog
- monitor your syslog
files.