Wi-Fi Protected Access II (WPA2) handshake traffic can be manipulated to induce nonce and session key reuse, resulting in key reinstallation by a wireless access point (AP) or client. An attacker within range of an affected AP and client may leverage these vulnerabilities to conduct attacks that are dependent on the data confidentiality protocols being used. Attacks may include arbitrary packet decryption and injection, TCP connection hijacking, HTTP content injection, or the replay of unicast and group-addressed frames.
Debian-security for jessie is already patched - we have to double check that we ship patched versions in nightly releases.
Affects: any systems that act like WiFi clients.
Severity: high (MITM attack of unauthorized attacker is possible)
Original investigator's site: https://www.krackattacks.com/
CERT: http://www.kb.cert.org/vuls/id/228519
UPSTREAM patches: https://w1.fi/security/2017-1/
Overview: https://habrahabr.ru/company/pentestit/blog/340182/
Debian security: https://www.debian.org/security/2017/dsa-3999