CVE-2016-1549 json
A malicious authenticated peer can create arbitrarily-many ephemeral associations in order to win the clock selection algorithm in ntpd in…
published 2017-01-06 9 y ago modified 2026-06-17 4 mo ago also EUVD-2016-2644
- cvss
- 6.5
- version 3.0, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 3.1%
- EPSS 3.1% chance of exploitation in 30 days, percentile 87%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- ntp Debian 11 1:4.2.8p7+dfsg-1
debian advisories DEBIAN-CVE-2016-1549
- ntp SLES 12 SP3, SLES 12 SP2-BCL, SLED 12 SP3 +7 more 4.2.8p11-64.5.1
- ntp SLES for SAP 12 SP3, SLES 12 SP3, SLED 12 SP3 4.2.8p11-64.3.2
- ntp SLES for SAP 11 SP4, SLES 11 SP4 4.2.8p11-64.4.1
- ntp SLES for SAP 12, SLES 12, SLED 12 4.2.8p8-46.8.1
- ntp SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLES 11 SP2-LTSS +3 more 4.2.8p7-44.1
- ntp SLES 12 SP1, SLES 11 SP4, SLED 12 SP1 +2 more 4.2.8p7-11.1
- ntp SLES 12-LTSS 4.2.8p11-46.26.2
suse advisories SUSE-SU-2018:1765-2SUSE-SU-2018:1765-1SUSE-SU-2018:1464-1SUSE-SU-2018:0956-1SUSE-SU-2018:0808-1SUSE-SU-2016:1568-1
- ntp openSUSE Tumbleweed 4.2.8p9-1.1
opensuse advisories openSUSE-SU-2024:10181-1
- ntp Arch Linux 4.2.8.p11-1
arch linux advisories AVG-647
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2016-1549 updated cvss 3.5
ntp: ephemeral association time spoofing
-
Red Hat Enterprise Linux 5 ntp Red Hat Enterprise Linux 6 ntp, ntpdate, ntp-perl Red Hat Enterprise Linux 7 ntp, sntp, ntpdate, ntp-perlaffected: workaround, no fix planned “Assure only trusted hosts have access to the trustedkey.”
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
3.12% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.0 | 6.5 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
| NVD | 2.0 | 4.0 | AV:N/AC:L/Au:S/C:N/I:P/A:N |
Affected products
- NTP Project NTP
- NTPsec Project NTPSec
Classification
- Weakness
-
- CWE-19 Data Processing Errors
References
-
security.freebsd.org
/advisories/FreeBSD-SA-16:16.ntp.asc
vendor-advisory
-
security.gentoo.org
/glsa/201607-15
vendor-advisory
-
talosintelligence.com
/reports/TALOS-2016-0083/
mitigation, technical-description, third-party-advisory
-
securityfocus.com
/bid/88200
vdb-entry
-
securitytracker.com
/id/1035705
vdb-entry
- oracle.com /technetwork/topics/security/bulletinapr2016-2952098.html
- security.netapp.com /advisory/ntap-20171004-0002/
- synology.com /support/security/Synology_SA_18_13
- support.hpe.com /hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_us
Sources
- CVE List CVE-2016-1549
- NVD CVE-2016-1549
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