A new exploitation technique called key reinstallation attacks used to break Wi-Fi handshakes that negotiate session keys was discovered. These attacks target the Wi-Fi/WPA2 standard. An adversary can trick a client or Access Point (AP) into reinstalling an already-in use pairwise key in 4-way handshake. While reinstalling the already in-use key, the associated packet number (sometimes also called nonce) and receive replay counter is reset. This causes nonce reuse, voiding any security the underlying encryption protocol is supposed to provide. For example, it allows decryption or injection of frames, and enables an attacker to replay frames.

Heap-based buffer overflow in the eapservertlsprocessfragment function in eapservertlscommon.c in the EAP authentication server in hostapd 0.6 through 1.0 allows remote attackers to cause a denial of service (crash or abort) via a small "TLS Message Length" value in an EAP-TLS message with the "More Fragments" flag set.