A new exploitation technique called key reinstallation attacks (KRACK) affecting WPA2 has been discovered. A remote attacker within Wi-Fi range could exploit this attack to decrypt Wi-Fi traffic or possibly inject forged Wi-Fi packets by reinstalling a previously used Tunneled Direct-Link Setup (TDLS) Peerkey (TPK) key during a TDLS handshake.
Wi-Fi Protected Access II (WPA2) handshake traffic can be manipulated to induce nonce and session key reuse, resulting in key reinstallation by a victim wireless access point (AP) or client. After establishing a man-in-the-middle position between an AP and client, an attacker can selectively manipulate the timing and transmission of messages in the WPA2 Tunneled Direct-Link Setup (TDLS) PeerKey (TPK) handshake, resulting in out-of-sequence reception or retransmission of messages.
An attacker within the wireless communications range of an affected AP and client may leverage these vulnerabilities to conduct attacks that are dependent on the data confidentiality protocol being used. Attacks may include arbitrary packet decryption and injection, TCP connection hijacking, HTTP content injection, or the replay of unicast, broadcast, and multicast frames.
Upstream: Mathy Vanhoef (University of Leuven)
Initital support for TDLS came with 1.0. RHEL6 does not provide support for TDLS and should not be affected.
RHEL7 already has the patch to prevent TDLS TPK M2 retransmission: https://w1.fi/cgit/hostap/commit/?id=dabdef9e048b17b22b1c025ad592922eab30dda8
This only leaves TDLS TPK M3, where the attack is believed to be of rather theoretical nature, unless WEP is used. However, WEP is already broken and should not be used, so there's little to gain for an attacker.
Created hostapd tracking bugs for this issue:
Affects: fedora-all [bug 1502588]
Created wpa_supplicant tracking bugs for this issue:
Affects: fedora-all [bug 1502589]
The upstream advisory suggests that this doesn't affect wpa_supplicant v. 2.6, that is shipped with Fedora 25 and newer (all supported Fedora versions) and RHEL 7.4, if I'm reading that correctly:
> For the TDLS TPK M2 retransmission issue (CVE-2017-13086) with older
> wpa_supplicant versions, consider updating to the latest version or
> merge in a commit that is present in v2.6:
> ('TDLS: Ignore incoming TDLS Setup Response retries')
This issue has been addressed in the following products:
Red Hat Enterprise Linux 7
Via RHSA-2017:2907 https://access.redhat.com/errata/RHSA-2017:2907
This issue did not affect the versions of wpa_supplicant as shipped with Red Hat Enterprise Linux 5 and 6, as it does not support TDLS.
This issue affects the versions of wpa_supplicant as shipped with Red Hat Enterprise Linux 7.