NTP or Network Time Protocol is a networking protocol for clock synchronization. A vulnerability in NTP could be used to carry out a DDoS attack. During this kind of attack, unsecure network services are misused using IP spoofing, which allows an unauthorized person to get a response considerably larger than the request.
Recommendations for users:
- Disable the NTP service;
- Set NTP to only be accessible from an internal network, or disable NTP readvar queries.