MEDIUM
CVE-2016-1547
CWE-20Published: January 6, 2017· Updated: Jun 17, 2026
5.3
CVSS v3.1
Official Description
An 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.
Technical Analysis
CVE-2016-1547 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityLow
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected Vendors & Products
ntp1 product(s)
ntp
Source: NVD CPE · 1 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (30)
→
http://www.talosintelligence.com/reports/TALOS-2016-0081/Mitigation · Technical Description · Third Party Advisory
Quick Facts
CVE IDCVE-2016-1547
CVSS Score5.3 / 10
SeverityMEDIUM
WeaknessCWE-20
CISA KEVNo
Affected1 vendor(s)
PublishedJan 6, 2017
Related CVEs (CWE-20)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2016-1547 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.