CVE-2016-1547 Denial of service in NTP
An off-path attacker can disrupt NTP client associations by sending spoofed crypto NAK packets, causing denial of service even with authentication enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2016-1547?
CVE-2016-1547 is a medium-severity denial of service vulnerability in Ntp Ntp, published on 6 Jan 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An off-path attacker can cause a preemptible client association to be demobilized in NTP 4.2.8p4 and earlier and NTPSec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 by sending a crypto NAK packet to a victim client with a spoofed source address of an existing associated peer. This is true even if authentication is enabled.
Weakness: CWE-20
Which versions are affected by CVE-2016-1547?
It affects 1 product.
Products include Ntp Ntp.
How do I fix CVE-2016-1547?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2016-1547 being exploited?
There is no known exploitation of CVE-2016-1547 in the wild and no public exploit code.
Other vulnerabilities in Ntp Ntp
Sources
Also known as DEBIAN-CVE-2016-1547, GHSA-hqqw-v32x-33cf, UBUNTU-CVE-2016-1547.