I don't usually dedicate much space here for jailbreaking news, but it's a Saturday and news is slow. The Chronic dev team has released a new version of their GreenPois0n jailbreak for iOS 4.2.1. This is version RC6 for both Mac OS X and Windows.

• Mac OS X
• Windows

No word yet on when the Linux version listed on their site will be released. In addition to setting your iPhone 4, iPhone 3GS, iPad or later generation iPods free, this version will now also jailbreak the second generation Apple TV. This is an untethered jailbreak, meaning you can boot up your iOS device without being plugged into a computer. Download and execute at your own risk.

If the fact that the iPhone and other iOS devices are jailbroken by basically exploiting security flaws in Apple's programming wasn't enough to highlight Apple's lack of security prowess, a Brazilian iPhone hacker by the name of Salomão Filho has found a new and much simpler flaw. This one is in Phone.app, and it allows anyone to bypass the security lock code on an iPhone to access the phone functions, thus allowing them to make calls and access contact information and voicemail. And it can be done by just about anyone with thumbs, via Neowin:

To bypass any lock screen simply hit "emergency call", then enter three pound signs, hit the green call button and immediately press the lock button and you will have bypassed the security feature on the iPhone.

According to Tipb this exploit has already been fixed in iOS 4.2 betas. It's unknown if Apple will release a pre-4.2 update to correct this issue. For now the only known workaround is not to lose your phone. Good luck! Thanks to @hasanahmad for the heads up.