Apple has released iOS 4.3.4 that patches PDF vulnerability in Mobile Safari discovered by Comex in JailbreakMe 3.0. Alongside with iOS 4.3.4 for iPhone 4 (GSM) and other devices, Apple has also released iOS 4.2.9 for Verizon iPhone 4 to fix the PDF exploit. To get your Verizon iPhone 4 on 4.2.9, simply open iTunes and connect your device to your computer. iTunes will automatically prompt you to update your devices’ firmware to 4.2.9. Click Download and update to update your Verizon iPhone 4.
If you want to manually download iOS 4.2.9, here’s the download link
Download iOS 4.2.9 for CDMA Verizon iPhone 4