CAPEC-486 - UDP Flood

An adversary may execute a flooding attack using the UDP protocol with the intent to deny legitimate users access to a service by consuming the available network bandwidth. Additionally, firewalls often open a port for each UDP connection destined for a service with an open UDP port, meaning the firewalls in essence save the connection state thus the high packet nature of a UDP flood can also overwhelm resources allocated to the firewall. UDP attacks can also target services like DNS or VoIP which utilize these protocols. Additionally, due to the session-less nature of the UDP protocol, the source of a packet is easily spoofed making it difficult to find the source of the attack.






This type of an attack requires the ability to generate a large amount of UDP traffic to send to the desired port of a target service using UDP.

To mitigate this type of an attack, modern firewalls drop UDP traffic destined for closed ports, and unsolicited UDP reply packets. A variety of other countermeasures such as universal reverse path forwarding and remote triggered black holing(RFC3704) along with modifications to BGP like black hole routing and sinkhole routing(RFC3882) help mitigate the spoofed source IP nature of these attacks.