A flaw was found in the implementation of EAP-pwd in FreeRADIUS. An attacker could initiate several EAP-pwd handshakes to leak information, which can then be used to recover the user's WiFi password by performing dictionary and brute-force attacks.
Created freeradius tracking bugs for this issue:
Affects: fedora-all [bug 1737664]
EAP-PWD support was first added in freeradius 3.0.0, so earlier versions as shipped in Red Hat Enterprise Linux 6 and earlier are not affected.
This issue did not affect the versions of freeradius as shipped with Red Hat Enterprise Linux 5, and 6 as they did not include support for EAP-pwd.
Given a random EAP-pwd token an attacker can learn if all 10 iterations of the compute_password_element() function failed. This happens once every 2048 handshakes and in that case an error frame is sent to the client. This information could be abused by an attacker to brute force the password, as in the Dragonblood attack.