CVE-2016-1549

Severity: medium (CVSS 6.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2017-01-06 · updated 2026-06-17
Weakness: CWE-19

Description

A malicious authenticated peer can create arbitrarily-many ephemeral associations in order to win the clock selection algorithm in ntpd in NTP 4.2.8p4 and earlier and NTPsec 3e160db8dc248a0bcb053b56a80167dc742d2b74 and a5fb34b9cc89b92a8fef2f459004865c93bb7f92 and modify a victim's clock.

Affected products

NTP: 4.2.8-p4

References

http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
http://www.securityfocus.com/bid/88200
http://www.securitytracker.com/id/1035705
http://www.talosintelligence.com/reports/TALOS-2016-0083/
https://security.FreeBSD.org/advisories/FreeBSD-SA-16:16.ntp.asc
https://security.gentoo.org/glsa/201607-15
https://security.netapp.com/advisory/ntap-20171004-0002/
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_us
https://www.synology.com/support/security/Synology_SA_18_13
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
http://www.securityfocus.com/bid/88200
http://www.securitytracker.com/id/1035705

Get alerted when CVE-2016-1549 or the next vulnerability affects your stack