CVE-2016-1549 — A malicious authenticated peer can create arbitrarily-many ephemeral association

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&

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
NTP Project	NTP	4.2.8p3, 4.2.8p4
NTPsec Project	NTPSec	3e160db8dc248a0bcb053b56a80167dc742d2b74, a5fb34b9cc89b92a8fef2f459004865c93bb7f92

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2017-01-06T21:00:00.000Z
• Last modified: 2024-08-05T23:02:12.001Z

09References

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