CVE-2016-1551

low
Published 2017-01-27 · Modified 2026-05-13
CVSS v3
3.7
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS v2
2.6
VIR risk
3.7

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.

Predictions

Exploit likelihood
47%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2016-1551

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2016-1551.html

OS impact

OSVersionStatusFixed in
suse slesaffected
debian debianbullseyefixed0

Application impact

VendorProductVersionsFixed
ntpntp4.2.8
ntpsecntpseca5fb34b9cc89b92a8fef2f459004865c93bb7f92

References

CWEs

CWE-254

Verify integrity in audit chain (admin only). AS-IS.