A vulnerability found in the NTP server makes it possible for an authenticated remote user to crash ntpd via a malformed mode configuration directive. Mitigation: Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.
Acknowledgments: Name: the NTP project Upstream: Cure53
Created ntp tracking bugs for this issue: Affects: fedora-all [bug 1435163]
In ntp-4.2.6p5 and ntp-4.2.4p8, the ttl value is an unsigned char (rather than uint32), limiting the OOB read to a (256-8)-byte region. Testing on x86_64 fails to cause a crash. Different compiler or linker options, or different hardware, could still result in a crash being possible through this vector.
Is RHEL-7 vulnerable to this?
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Via RHSA-2017:3071 https://access.redhat.com/errata/RHSA-2017:3071
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2018:0855 https://access.redhat.com/errata/RHSA-2018:0855