14 Sep 2016

Interesting times, 2016 edition

Everyone’s favorite security analyst Bruce Schneier seems to think that somebody is learning how to “take down the Internet” by repeatedly probing key pieces of “basic infrastructure” – exactly what’s being probed isn’t stated, but the smart money is on the DNS root servers. Naturally, who is doing this is left unsaid as well, although Schneier does at least hazard the obvious guess at China and Russia.

If this is true, it’s a seemingly sharp escalation towards something that might legitimately be called ‘cyberwarfare’, as opposed to simply spying-using-computers, which is most of what gets lumped in under that label today. Though, it’s not clear exactly why a state-level actor would want to crash DNS; it’s arguably not really “taking down the Internet”, although it would mess up a lot of stuff for a while. Even if you took down the root DNS servers, it wouldn’t stop IP packets from being routed around (the IP network itself is pretty resilient), and operators could pretty quickly unplug their caching DNS resolvers and let them run independently, restoring service to their users. You could create a mess for a while, but it wouldn’t be crippling in the long term.

Except perhaps as one component of a full-spectrum, physical-world attack, it doesn’t make a ton of sense to disrupt a country’s DNS resolvers for a few hours. And Russia and China don’t seem likely to actually attack the U.S. anytime soon; relations with both countries seem to be getting worse over time, but they’re not shooting-war bad yet. So why do it?

The only reason that comes to mind is that it’s less ‘preparation’ than ‘demonstration’. It’s muscle flexing on somebody’s part, and not particularly subtle flexing at that. The intended recipient of the message being sent may not even be the U.S., but some third party: “see what we can do to the U.S., and imagine what we can do to you”.

Or perhaps the eventual goal is to cover for a physical-world attack, but not against the U.S. (where it would probably result in the near-instant nuclear annihilation of everyone concerned). Perhaps the idea is to use a network attack on the U.S. as a distraction, while something else happens in the real world? Grabbing eastern Ukraine, or Taiwan, just as ideas.

Though an attack on the DNS root servers would be inconvenient in the short run, I am not sure that in the long run that it would be the worst thing to happen to the network as an organism: DNS is a known weakness of the global Internet already, one that desperately needs a fix but where there’s not enough motivation to get everyone moving together. An attack would doubtless provide that motivation, and be a one-shot weapon in the process.

Update: This article from back in April, published by the ‘Internet Governance Project’, mentions a Chinese-backed effort to weaken US control over the root DNS, either by creating additional root servers or by potentially moving to a split root. So either the probing or a future actual disruption of DNS could be designed to further this agenda.

In 2014, [Paul] Vixie worked closely with the state-owned registry of China (CNNIC) to promote a new IETF standard that would allow the number of authoritative root servers to increase beyond the current limit of 13. As a matter of technical scalability, that may be a good idea. The problem is its linkage to a country that has long shown a more than passing interest in a sovereign Internet, and in modifying the DNS to help bring about sovereign control of the Internet. For many years, China has wanted its “own” root server. The proposal was not adopted by IETF, and its failure there seems to have prompted the formation and continued work of the YETI-DNS project.

The YETI-DNS project appears, at the moment, to be defunct. Still, China would seem to have the most to gain by making the current U.S.-based root DNS system seem fragile, given the stated goal of obtaining their own root servers.

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