I have gone through the paper (PDF) available at krackattacks.com.
However, from what I understood you force a key reinstallation causing you a nonce reuse over 2 blob of data. As it is a keystream, you might be able to decrypt the data.
Limitations are:
- You MUST know clear text of one of both data
- It is one shot as the counter gets incremented, you need to perform another key reinstallation to be able to decrypt further data
This doesn't sound very practical in my point of view, am I missing something?