ANSWERS / IPHONEAsk Question Can I upgrade my firmware to the newest and still use ultrasn0w for unlock? LIKE TWEET SHARE PIN SHARE POST MAIL MORE 0 pablomerio • February 10, 2013 at 4:52pm My iPhone 4 is currently with firmware 4.3.3 (8J2) and 01.50.00 Modem Firmware. Thanks. Follow · CommentAnswers0 QC Wireless • February 12, 2013 at 6:28am NO Comment