Date Added: Jul 2010
Cisco access points support WPA Migration Mode, which enables both WPA and WEP clients to associate to an access point using the same Service Set Identifier (SSID). Cisco warns (inside a Q&A document) about the dangers by stating "That security will operate at the least-secure level common to all devices" and "as a result, a passive WEP key attack could be launched against WEP users". The scenario where WEP clients are connected is a serious risk; besides "A passive WEP key attack", an active WEP cracking attack against a connected WEP client station (i.e. not the access point) could be launched, leveraging the WEP key in minutes.