Security researchers have discovered several key management vulnerabilities in the core of Wi-Fi Protected Access II (WPA2) protocol that could allow an attacker to hack into your Wi-Fi network and eavesdrop on the Internet communications.
WPA2 is a 13-year-old WiFi authentication scheme widely used to secure WiFi connections, but the standard has been compromised, impacting almost all Wi-Fi devices—including in our homes and businesses, along with the networking companies that build them.
Dubbed KRACK—Key Reinstallation Attack—the proof-of-concept attack demonstrated by a team of researchers works against all modern protected Wi-Fi networks and can be abused to steal sensitive information like credit card numbers, passwords, chat messages, emails, and photos.
Since the weaknesses reside in the Wi-Fi standard itself, and not in the implementations or any individual product, any correct implementation of WPA2 is likely affected.
According to the researchers, the newly discovered attack works against:
Both WPA1 and WPA2,
Personal and enterprise networks,
Ciphers WPA-TKIP, AES-CCMP, and GCMP
In short, if your device supports WiFi, it is most likely affected. During their initial research, the researchers discovered that Android, Linux, Apple, Windows, OpenBSD, MediaTek, Linksys, and others, are all affected by the KRACK attacks.
The researchers say their key reinstallation attack could be exceptionally devastating against Linux and Android 6.0 or higher, because "Android and Linux can be tricked into (re)installing an all-zero encryption key (see below for more info)."
However, there's no need to panic, as you aren't vulnerable to just anyone on the internet because a successful exploitation of KRACK attack requires an attacker to be within physical proximity to the intended WiFi network.
Source.