FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

ntpd DRDoS / Amplification Attack using ntpdc monlist command

Affected packages
ntp < 4.2.7p26
8.3 <= FreeBSD < 8.3_14
8.4 <= FreeBSD < 8.4_7
9.1 <= FreeBSD < 9.1_10
9.2 <= FreeBSD < 9.2_3


VuXML ID 3d95c9a7-7d5c-11e3-a8c1-206a8a720317
Discovery 2014-01-01
Entry 2014-01-14
Modified 2016-08-09 reports:

Unrestricted access to the monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote attackers to cause a denial of service (traffic amplification) via forged (1) REQ_MON_GETLIST or (2) REQ_MON_GETLIST_1 requests, as exploited in the wild in December 2013

Use noquery to your default restrictions to block all status queries.

Use disable monitor to disable the ``ntpdc -c monlist'' command while still allowing other status queries.


CVE Name CVE-2013-5211
FreeBSD Advisory SA-14:02.ntpd