Hacker George Hotz released “blacksn0w,” a combination jailbreak and unlock tool that works for iPhone 3G and iPhone 3GS. The free software is noteworthy because it is first known successful jailbreak and unlock for iPhone 3GS with iPhone OS 3.1.2 and baseband 05.11.07. Apple updated BootROM for iPhone 3GS to iBoot-359.32 in with a mid-cycle hardware release in October — first time ever that handset maker had modified its hardware in middle of a product line, without a new model released. Prior to new BootROM, hackers relied on an exploit known as “24kpwn,” which allowed users to run unauthorized code on OS. But latest update had prevented that exploit. Latest hack for newly updated iPhone 3GS hardware isn’t as seamless as some previous exploits. The blacksn0w software applies what’s known as a “tethered jailbreak” for October-and-later iPhone 3GS (and latest iPod touch), meaning users cannot perform a hardware reset of phone without connecting it via USB cable to a computer. Users of an iPhone 3G or iPhone 3GS sold prior to latest hardware upgrade’re said to be able to restart without tethered jailbreak.