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Microsoft Has Already Fixed the Wi-Fi Attack Vulnerability; Android Will Be Patched Within Weeks (theverge.com)
Microsoft says it has already fixed the problem for customers running supported versions of Windows. From a report: "We have released a security update to address this issue," says a Microsoft spokesperson in a statement to The Verge. "Customers who apply the update, or have automatic updates enabled, will be protected. We continue to encourage customers to turn on automatic updates to help ensure they are protected." Microsoft is planning to publish details of the update later today. While it looks like Android and Linux devices are affected by the worst part of the vulnerabilities, allowing attackers to manipulate websites, Google has promised a fix for affected devices "in the coming weeks." Google's own Pixel devices will be the first to receive fixes with security patch level of November 6, 2017, but most other handsets are still well behind even the latest updates. Security researchers claim 41 percent of Android devices are vulnerable to an "exceptionally devastating" variant of the Wi-Fi attack that involves manipulating traffic, and it will take time to patch older devices.
"The key negotiation process needs to allow for the possibility of radio interference, so it permits the access point to re-send the message that is step three of the handshake. If an attacker sends a copy of this message, the client device will be tricked into reverting back to the original encryption key and initialization vector used at the start of the session. The client's next transmissions will have been encrypted with the same key as earlier transmissions, even though that key was only meant for a single use. That allows for a key reuse attack, which doesn't directly expose the underlying encryption key but does make it relatively easy to decrypt the data that was encrypted, especially if something is known about the structure of the messages that were both encrypted with the same key. IP packet headers, in turn, provide exactly that."
Yes, if the phase 3 handshake re-transmit required by the specification inherently enables a key reuse attack, then the flaw is not in the implementation, but the specification itself, and security would dictate that one refuse to enable that portion of the specification. Losing the ability to initialize a connection in a high RFI environment, which most installations attempt to avoid and mitigate, is an inconvenience. Having your traffic snooped is quite a bit more of an issue.