Mar 21 2021

Dirt Cheap DDoS for Hire, via D/TLS Amplification

Category: DDoS,Information SecurityDISC @ 10:33 pm

A new way of sending powerful denial of service traffic emerged this week. Malefactors are now misusing servers that talk Datagram Transport Layer Security (D/TLS).

Typified by Cisco’s Netscaler ADC product, before a patch was released in January, some D/TLS servers don’t check for forged requests. That allows scrotes to misuse these high-bandwidth servers to deny internet service to people they want to extort money from.

This possibly includes Sony, whose LittleBigPlanet service has been AWOL for a week. In today’s SB Blogwatch, we ask the question.

Your humble blogwatcher curated these bloggy bits for your entertainment. Not to mention: But is it art?

Dirty Deeds: DDoS D/TLS

What’s the craic? Dan Goodin reports in—“~4,300 publicly reachable servers are posing a new DDoS hazard to the Internet”:

 DDoSes are attacks that flood a website or server with more data than it can handle. The result is a denial of service to people trying to connect to the service. As DDoS-mitigation services develop protections … the criminals respond with new ways to make the most of their limited bandwidth.

In so-called amplification attacks, DDoSers send requests of relatively small data sizes to certain types of intermediary servers. … DDoS-for-hire services [are] adopting a new amplification vector … D/TLS, which (as its name suggests) is essentially the Transport Layer Security for UDP data packets.

The biggest D/TLS-based attacks Netscout has observed delivered about 45 Gbps of traffic. The people responsible for the attack combined it with other amplification vectors to achieve a combined size of about 207 Gbps.

Abusable D/TLS servers are the result of misconfigurations or outdated software that causes an anti-spoofing mechanism to be disabled. While the mechanism is built in to the D/TLS specification, hardware including the Citrix Netscaler Application Delivery Controller didn’t always turn it on by default.

Dirt Cheap DDoS for Hire, via D/TLS Amplification

Tags: DDoS D/TLS

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