### [CVE-2016-4955](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-4955)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

ntpd in NTP 4.x before 4.2.8p8, when autokey is enabled, allows remote attackers to cause a denial of service (peer-variable clearing and association outage) by sending (1) a spoofed crypto-NAK packet or (2) a packet with an incorrect MAC value at a certain time.

### POC

#### Reference
- http://packetstormsecurity.com/files/137321/Slackware-Security-Advisory-ntp-Updates.html
- http://packetstormsecurity.com/files/137322/FreeBSD-Security-Advisory-FreeBSD-SA-16-24.ntp.html
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html

#### Github
No PoCs found on GitHub currently.