The notice may be read in it's entirety at
https://www.us-cert.gov/ncas/alerts/TA14-017A.
Original release date: January 17, 2014 | Last revised: February 09, 2014.
Certain UDP protocols have been identified as potential attack vectors:
DNS
NTP
SNMPv2
NetBIOS
SSDP
CharGEN
QOTD
BitTorrent
Kad
Quake Network Protocol
Steam Protocol
The Mitigation section of the notice describes a suggested method and provides an open-source verification software package for verifying ingress filtering (a recommended practice).
There are links to documents and prior notices that may be of interest.
Hope this helps some.
