It is well known that WEP encryption isn't very safe. The problem is that now it can be done in less than 2 minutes with a 95% of success :O
It works as previous attacks, by taking traffic and analyzing it to obtain the cypher key.
And that's not all... all of these being done with a normal laptop (Pentium-M @ 1,7GHz), which means anybody can do it.
Source: ars Technica