wpa_supplicant fails group key attacks even after krack patch

Jouni Malinen j at w1.fi
Tue Dec 5 02:27:05 PST 2017

On Sun, Dec 03, 2017 at 02:04:27PM -0800, David Park wrote:
> I downloaded and cross-compiled wpa_supplicant for ARM from commit
> a0e3e22 which had all the patches relating to KRACK.
> Using the vulnerability detection tool from the wifi alliance, I am
> now passing all the pairwise tests, but not the group key related
> tests. Specifically, I am failing the 4.1.3 and 4.2.1.
> My wifi driver is part of the mainline kernel, interfacing with
> mac82011 and cfg82011, so I would have thought all the KRACK
> vulnerabilities would be completely handled by the wpa_supplicant
> patches. Is there something I'm missing?

Assuming that wpa_supplicant build does indeed include the applicable
patches, I would assume this is showing an issue in replay protection:

> [17:34:45] d0:c1:93:02:ed:72: Received 5 unique replies to replayed
> broadcast ARP requests. Client is vulnerable to group
> [17:34:45]                    key reinstallations in the 4-way
> handshake (or client accepts replayed broadcast frames)!

i.e., that "client accepts replayed broadcast frames" part. You may need
WLAN driver and/or firmware fixes to address that (the actual CCMP
replay protection is performed at lower layers than wpa_supplicant).

Jouni Malinen                                            PGP id EFC895FA

More information about the Hostap mailing list