A new DDoS attack vector: TCP Middlebox Reflection
In August 2021, researchers from the University of Maryland and the University of Colorado Boulder published an award-winning paper detailing a potential DDoS attack vector that takes advantage of flaws within the middleboxes of TCP protocols and can be abused to launch massive Distributed Denial of Service (DDoS) attacks. In March 2022, security researchers at Akamai Security Operations Command Center detected and analysed a series of TCP reflection attacks, peaking at 11Gbps at 1.5 million packets per second (Mpps). Upon examining the TCP packets used in the attack, they realized the attackers were leveraging the technique outlined in the above paper, which they termed TCP Middlebox Reflection attack. In this attack, the attacker abuses vulnerable firewalls and content filtering systems to reflect and amplify TCP traffic to a victim’s machine, creating a powerful DDoS attack. A middlebox is a computer networking device that transforms, inspects, filters, and manipulates traffic for purposes other than packet forwarding. Firewalls, NAT devices, load balancers, and deep packet inspection (DPI) devices are common examples of middleboxes. The researchers who first detailed the attack described two methods to detect potentially vulnerable middleboxes. Using these scanning methods, Shadowserver researchers found that more than 18.8 million IPs are vulnerable to Middlebox TCP Reflection DDoS attacks, which can also be leveraged to launch TCP-based DDoS Reflection attacks. You can get check if any of your IPs are on this list by subscribing to the Shadowserver ‘Vulnerable DDoS Middlebox Report’.








