Hello All,
I am newbie to wireless and I installed 2 wireless access point in bridge or infrastructure mode. Each of AP has its neighbour mac address listed in its configuration. Both of them are connected using wep 128 bit key.  I was wondering if it is secure or not?. If it is possible to crack wep key in the bridge mode as described above?. Is it possible to do the MITM between those 2 AP and if it is what tools would be require in order to perform MITM?.

Touching on what slimjim said if you can capture some IV packets (interesting packets) you can use airreplay to crack the keys faster.  On a basic home network you would probably have to sniff traffic quite awhile to get enough IV packets to crack the wep key.  Airreplay will allow you to do it alot faster.  You can also check out cain as the new versions have a wireless cracking feature built in.