ntpd in NTP 4.2.8p3 and NTPsec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 relies on the…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA.
Summary
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.
Why it matters now
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 · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ntp:ntp:4.2.8:p3:*:*:*:*:*:* | 4.2.8 p3 | Vulnerable | NTP Project |
| cpe:2.3:a:ntpsec:ntpsec:a5fb34b9cc89b92a8fef2f459004865c93bb7f92:*:*:*:*:*:*:* | a5fb34b9cc89b92a8fef2f459004865c93bb7f92 | Vulnerable | NTPsec |
- cpe:2.3:a:ntp:ntp:4.2.8:p3:*:*:*:*:*:* Versions 4.2.8 p3 Vulnerable ·NTP Project
- cpe:2.3:a:ntpsec:ntpsec:a5fb34b9cc89b92a8fef2f459004865c93bb7f92:*:*:*:*:*:*:* Versions a5fb34b9cc89b92a8fef2f459004865c93bb7f92 Vulnerable ·NTPsec
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
Not affected: 3 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2016-1551
- 2026-10-03 Alias added: GHSA-xhrh-m85j-g7hf
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-2016-1551 · CVE Program
- CVE-2016-1551 · NVD
- FIRST EPSS
- GHSA-xhrh-m85j-g7hf · GitHub Advisory Database · CC BY 4.0
- CVE-2016-1551 · Red Hat security data · CC BY 4.0
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