I was reading an article on Great Cannon at Ars Technica (http://arstechnica.com/security/2015/04/meet-great-cannon-the-man-in-the-middle-weapon-china-used-on-github/) and it seems to me that this is basically a JavaScript injection attack which was then used to perform a DDoS.

It sounds like the media is spinning this into a "new type" of attack. Even the name "Great Cannon" seems to indicate that this is something special.

Is there something I'm missing?


What the report shows is not the uniqueness of the attack vector, but the systemization of the attack vector as a part of a national defence strategy.

GC is an in-path system, capable of not only injecting traffic but also directly suppressing traffic, acting as a full “man-in-the-middle” for targeted flows.


In addition, in contrast to the GFW, the GC only examines individual packets in determining whether to take action, which avoids the computational costs of TCP bytestream reassembly. The GC also maintains a flow cache of connections that it uses to ignore recent connections it has deemed no longer requiring examination.

The issue, then, is the nationwide scope and reach for targeted, active response to websites with undesirable content.


Yes, essentially it is.

It is not what it is, but how it was achieved, which is what the hype is about.

It is a JavaScript injection attack on a global scale - both in terms of impact and in terms of the technological challenge to make it happen.

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