A malicious authenticated peer can create arbitrarily-many ephemeral associations in…
Priority LOW 34CWE-19Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat.
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.
Why it matters now
EPSS 0.03121 87th percentileScored 2026-11-07
Fix Will not fix Red Hat: no fix planned
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| NTP Project | NTP | 4.2.8p3; 4.2.8p4 | — | No fix listed | CNA |
| NTP Project | NTPSec | 3e160db8dc248a0bcb053b56a80167dc742d2b74; a5fb34b9cc89b92a8fef2f459004865c93bb7f92 | — | No fix listed | CNA |
- NTP VendorNTP Project Affected 4.2.8p3; 4.2.8p4 Fixed in — No fix listed CNA
- NTPSec VendorNTP Project Affected 3e160db8dc248a0bcb053b56a80167dc742d2b74; a5fb34b9cc89b92a8fef2f459004865c93bb7f92 Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ntp:ntp:4.2.8:p4:*:*:*:*:*:* | 4.2.8 p4 | Vulnerable | NTP Project |
- cpe:2.3:a:ntp:ntp:4.2.8:p4:*:*:*:*:*:* Versions 4.2.8 p4 Vulnerable ·NTP Project
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
Timeline
- 2026-10-02 Threatist record created from CVE-2016-1549
- 2026-10-03 Alias added: GHSA-r89j-r995-h68w
References
More NTP Project Ntp vulnerabilities
- TI-2015-06541 Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows… CVSS 3.1CRITICAL 9.8
- TI-2014-07543 Multiple stack-based buffer overflows in ntpd in NTP before 4.2.8 allow remote attackers… CVSS 2.0HIGH 7.5
- TI-2013-04524 The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote… CVSS 2.0MEDIUM 5.0
- TI-2016-06333 The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a… CVSS 3.1HIGH 7.5
- TI-2018-08842 Stack-based buffer overflow in ntpq and ntpdc of NTP version 4.2.8p11 allows an attacker… CVSS 3.0CRITICAL 9.8
- TI-2016-04280 ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon… CVSS 3.1HIGH 7.5
Sources
- CVE-2016-1549 · CVE Program
- CVE-2016-1549 · NVD
- FIRST EPSS
- GHSA-r89j-r995-h68w · GitHub Advisory Database · CC BY 4.0
- CVE-2016-1549 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences