Plug your iPhone into iTunes today and you’ll be able to update your phone to iOS 4.02. The main purpose of the update is to fix a security flaw with PDF files – it had been discovered that downloading a PDF file in Safari could have allowed potentially malicious files access to your phone.
The secondary purpose is to stop jailbreaking. Jailbreakme offered one click iPhone jailbreaking that used the PDF security flaw. So upgrading to 4.02 will kill your jailbreak, but make the phone more secure.
Surprisingly, the update is over 500mb, a lot for an supposed security fix. I wonder if there are some stability fixes in there too, as iOS4 has definitely been more buggy than 3 (at least on my 3GS).
Check out Apple’s info on the update, where you can also see the iOS 3.2.2 update for the iPad that fixes the same problem.
