CVE-2016-1548
CWE-19Published: January 6, 2017· Updated: Jun 17, 2026
Official Description
An attacker can spoof a packet from a legitimate ntpd server with an origin timestamp that matches the peer->dst timestamp recorded for that server. After making this switch, the client in NTP 4.2.8p4 and earlier and NTPSec aa48d001683e5b791a743ec9c575aaf7d867a2b0c will reject all future legitimate server responses. It is possible to force the victim client to move time after the mode has been changed. ntpq gives no indication that the mode has been switched.
Technical Analysis
CVE-2016-1548 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.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (68)
Quick Facts
Related CVEs (CWE-19)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2016-1548 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts