Security researcher Mathy Vanhoef was at the forefront of discovering the holes in WPA2, finding 10 in all.
While the KRACK Wi-Fi exploit exposure has made billions of devices vulnerable, Windows users with enabled automatic updates can stay at ease.
From there, the hacker can spy on incoming and outgoing internet traffic and infect websites with malware or ransomware.
Affecting all Wi-fi tools in both individual and enterprise area, this reveals data such as a shared credit card, password, message, email, and photos on network.
An alert from the US Department of Homeland Security Computer Emergency Response Team on Monday said the flaw could be used within range of Wi-Fi using the WPA2 protocol to hijack private communications.
"If your device supports Wi-Fi, it is most likely affected", said Vanhoef.
The flaw affects operating systems and devices, including Android, Linux, Apple, Windows, MediaTek and others. The WPA2 system is a system which secures the Wi-Fi connection between a router and a computer. Potential attackers can access users' Internet traffic and intercept sensitive information.
As I've previously written, the padlock indicates that traffic to and from a site is encrypted - via the HTTPS protocol- which basically means no one but that site can read any sensitive information you share.
The best way to protect yourself at the moment is to ensure that all computing devices and mobile devices that connect with Wi-Fi are properly updated with the latest software and security patches.
Many businesses have already been briefed on the matter and we should expect to see a slew of patches being released all week to address this issue.
From reading the advisory on this flaw, it appears that the most recent versions of Windows and Apple's iOS are either not vulnerable to this flaw or are only exposed in very specific circumstances. Google has said that it will be rolling out the fix for Android devices in the coming weeks. However, news on either of those topics remains sparse, and ZDnet says as of this morning that "Wi-Fi should be considered a no-go zone for anything mission critical". While changing the password of your Wi-Fi network does not prevent or mitigate the attack, it's never a bad idea to change the Wi-Fi password, Vanhoef said. Connected devices such as security cameras, lighting and other electronic devices are at risk too.