Broken cryptography algorithms
Wi-Fi Protected Setup
Wi-Fi Protected Setup (WPS; originally, Wi-Fi Simple Config) is a network security standard to create a secure wireless home network. Created by Cisco and introduced in 2006, the point of the protocol is to allow home users who know little of wireless security and may be intimidated by the available security options to set up Wi-Fi Protected Access, as well as making it easy to add new devices to an existing network without entering long passphrases. Wi-Fi Protected Setup allows the owner of Wi-Fi privileges to block other users from using their household Wi-Fi. The owner can also allow people to use Wi-Fi. This can be changed by pressing the WPS button on the home router. A major security flaw was revealed in December 2011 that affects wireless routers with the WPS PIN feature, which most recent models have enabled by default. The flaw allows a remote attacker to recover the WPS PIN in a few hours with a brute-force attack and, with the WPS PIN, the network's WPA/WPA2 pre-shared key (PSK). Users have been urged to turn off the WPS PIN feature, although this may not be possible on some router models. (Wikipedia).
