CVE-2016-1551
ntpd in NTP 4.2.8p3 and NTPsec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 relies on the underlying operating system to protect it from…
- 3.7LowCVSS base score
- 2.2%Exploitation in 30 daysEPSS · top 17% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
ntpd in NTP 4.2.8p3 and NTPsec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 relies on the underlying operating system to protect it from requests that impersonate reference clocks. Because reference clocks are treated like other peers and stored in the same structure, any packet with a source ip address of a reference clock (127.127.1.1 for example) that reaches the receive() function will match that reference clock's peer record and will be treated as a trusted peer. Any system that lacks the typical martian packet filtering which would block these packets is in danger of having its time controlled by an attacker.
Timeline
ID reserved
By certcc
- 13 months later
· 13 months later
Published
- 8 years later
· 8 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.0 | Low3.7 | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 2.2% · top 17% of all CVEs (9 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.7.
Affected products
- affected 4.2.8p3
- affected 4.2.8p4
- affected 3e160db8dc248a0bcb053b56a80167dc742d2b74
- affected a5fb34b9cc89b92a8fef2f459004865c93bb7f92
References
7
- 88219 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- http://www.talosintelligence.com/reports/TALOS-2016-0132/ (opens in a new tab)x_refsource_MISCx_transferred
- 1035705 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://security.netapp.com/advisory/ntap-20171004-0002/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- FreeBSD-SA-16:16 (opens in a new tab)vendor-advisoryx_refsource_FREEBSDx_transferred
- GLSA-201607-15 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2016-2646 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2016-1551)Record last updated .