Previous posts (Part 1 and Part 2) offer background on DNS amplification attacks being observed around the world. These attacks continue to evolve. Early attacks focused on authoritative servers using "ANY" queries for domains that were well known to offer good amplification. Response Rate Limiting (RRL) was developed to respond to these early attacks. RRL, as the name suggests, is deployed on authoritative servers to rate limit responses to target names.
There are some real problems in DNS, related to the general absence of Source Address Validation (SAV) on many networks connected to the Internet. The core of the Internet is aware of destinations but blind to sources. If an attacker on ISP A wants to forge the source IP address of someone at University B when transmitting a packet toward Company C, that packet is likely be delivered complete and intact, including its forged IP source address. Many otherwise sensible people spend a lot of time and airline miles trying to improve this situation... The problems created for the Domain Name System (DNS) by the general lack of SAV are simply hellish.
This post follows an earlier post about DNS amplification attacks being observed around the world. DNS Amplification Attacks are occurring regularly and even though they aren't generating headlines targets have to deal with floods of traffic and ISP infrastructure is needlessly stressed -- load balancers fail, network links get saturated, and servers get overloaded. And far more intense attacks can be launched at any time.
Geoff Huston's recent post about the rise of DNS amplification attacks offers excellent perspective on the issue. Major incidents like the Spamhaus attack Geoff mentions at the beginning of his post make headlines, but even small attacks create noticeable floods of traffic. These attacks are easy to launch and effective even with relatively modest resources and we see evidence they're occurring regularly. Although DNS servers are not usually the target of these attacks the increase in traffic and larger response sizes typically stress DNS infrastructure and require attention from operation teams.
One of the most prominent denial of service attacks in recent months was one that occurred in March 2013 between Cloudflare and Spamhaus... How did the attackers generate such massive volumes of attack traffic? The answer lies in the Domain Name System (DNS). The attackers asked about domain names, and the DNS system answered. Something we all do all of the time of the Internet. So how can a conventional activity of translating a domain name into an IP address be turned into a massive attack?
When the domain name system (DNS) was first designed, security was an afterthought. Threats simply weren't a consideration at a time when merely carrying out a function - routing Internet users to websites - was the core objective. As the weaknesses of the protocol became evident, engineers began to apply a patchwork of fixes. After several decades, it is now apparent that this reactive approach to DNS security has caused some unintended consequences and challenges.
Most people - mistakenly - believe that they are perfectly safe behind a firewall, network address translation (NAT) device or proxy. The fact is quite the opposite: if you can get out of your network, someone else can get in. Attackers often seek to compromise the weakest link in a network and then use that access to attack the network from the inside, commonly known as a "pivot-and-attack."
My blog 'What PRISM, credit card hacking and Chromecast have to do with FttH' led to some very interesting discussions all around the world. One of issues that was discussed was that the sheer capacity of FttH will also allow hackers, criminals and others to use that massive capacity for the wrong reasons. Its volume will make it increasingly difficult to police.
The world of Internet threats has changed continually over the years. From the time that a "worm" first showed up in the wild, or whenever someone penetrated a system without authorization for the first time, various forms of attacks and malware have presented dangers to the system and those who use it. Different vectors have received varied focus over the years... Many parts of the Internet community have been involved in addressing relevant issues and fostering efforts to combat them.
In part one of this post we introduced the cyber response curve. In this post, we have outlined some observations which illustrate how different level of maturity and approaches can affect your cyber response curve.