CVE-2016-1547

Summary

CVECVE-2016-1547
StatePUBLISHED
Assignercertcc
Source PriorityCVE Program / NVD first with legacy fallback
Published2017-01-06 21:59:00 UTC
Updated2026-05-06 22:30:45 UTC
DescriptionAn off-path attacker can cause a preemptible client association to be demobilized in NTP 4.2.8p4 and earlier and NTPSec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 by sending a crypto NAK packet to a victim client with a spoofed source address of an existing associated peer. This is true even if authentication is enabled.

Risk And Classification

Primary CVSS: v3.0 5.3 MEDIUM from [email protected]

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS: 0.036640000 probability, percentile 0.879690000 (date 2026-05-11)

Problem Types: CWE-20 | unspecified


VersionSourceTypeScoreSeverityVector
3.0[email protected]Primary5.3MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
2.0[email protected]Primary5AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS v3.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS v2.0 Breakdown

Access Vector
Network
Access Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial

AV:N/AC:L/Au:N/C:N/I:N/A:P

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Ntp Ntp All p4 All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA NTP Project NTP affected 4.2.8p3 Not specified
CNA NTP Project NTP affected 4.2.8p4 Not specified
CNA NTPsec Project NTPSec affected a5fb34b9cc89b92a8fef2f459004865c93bb7f92 Not specified

References

ReferenceSourceLinkTags
Siemens TIM 4R-IE Devices | CISA af854a3a-2127-422b-91ae-364da2661108 us-cert.cisa.gov
April 2016 Network Time Protocol Daemon (ntpd) Vulnerabilities in Multiple NetApp Products | NetApp Product Security af854a3a-2127-422b-91ae-364da2661108 security.netapp.com
cert-portal.siemens.com/productcert/pdf/ssa-497656.pdf af854a3a-2127-422b-91ae-364da2661108 cert-portal.siemens.com
security.FreeBSD.org/advisories/FreeBSD-SA-16:16.ntp.asc af854a3a-2127-422b-91ae-364da2661108 security.FreeBSD.org
Security Advisory 0019 - Arista af854a3a-2127-422b-91ae-364da2661108 www.arista.com
Red Hat Customer Portal af854a3a-2127-422b-91ae-364da2661108 access.redhat.com
Red Hat Customer Portal af854a3a-2127-422b-91ae-364da2661108 rhn.redhat.com
cert-portal.siemens.com/productcert/pdf/ssa-211752.pdf af854a3a-2127-422b-91ae-364da2661108 cert-portal.siemens.com
NTP: Multiple vulnerabilities (GLSA 201607-15) — Gentoo Security af854a3a-2127-422b-91ae-364da2661108 security.gentoo.org
ntp Multiple Bugs Let Remote Users Spoof Messages, Obtain Potentially Sensitive Information, Modify Time, and Deny Service - SecurityTracker af854a3a-2127-422b-91ae-364da2661108 www.securitytracker.com
Cisco Talos - Talos 2016 0081 af854a3a-2127-422b-91ae-364da2661108 www.talosintelligence.com Mitigation, Technical Description, Third Party Advisory
NTP CVE-2016-1547 Denial of Service Vulnerability af854a3a-2127-422b-91ae-364da2661108 www.securityfocus.com
Debian -- Security Information -- DSA-3629-1 ntp af854a3a-2127-422b-91ae-364da2661108 www.debian.org
Oracle Linux Bulletin - April 2016 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com
Oracle Solaris Bulletin - April 2016 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Legacy QID Mappings

  • 590721 Siemens TIM 4R-IE Devices Multiple Vulnerabilities (ICSA-21-103-11)
  • 590736 Siemens SIMATIC NET CP 443-1 OPC UA Multiple Vulnerabilities (ICSA-21-159-11)
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