iOS 4.3.4 Software Update
Fixes security vulnerability associated with viewing malicious PDF files.
Products compatible with this software update:
iPhone 4 (GSM model)
iPod touch (4th generation)
iPod touch (3rd generation)
For information on the security content of this update, please visit this website:
*NOTE: iOS 4.2.9 is also out for Verizon iPhone 4s.