Along with iOS 4.3.4, Apple has also released iOS 4.2.9 for Verizon iPhone 4 CDMA. You can download iOS 4.2.9 for Verizon iPhone 4 from the link below. Like iOS 4.3.4, the Verizon iPhone 4.2.9 firmware also patches the PDF vulnerability in Mobile Safari exposed by JailbreakMe 3.0, the iOS 4.3.3 jailbreak tool by Comex.
ATTENTION: If you want to keep enjoying your untethered iOS 4.2.8 jailbreak, we strongly suggest you to stay away from iOS 4.2.9 firmware. iOS 4.2.9 is released just to patch the JailbreakMe 3.0 PDF exploit. There’s no need to install iOS 4.2.9 when jailbreakers can patch the exploit with PDF Patcher 2 available in Cydia.
How to Isntall iOS 4.2.9
Connect your iPhone/iPod Touch/iPad to iTunes, new firmware 4.2.9 availability message should appear, then hit the “Download and Install” button. (Not recommended for jailbreakers and unlockers)
You can also download iOS 4.2.9 firmware from the links below. Hold down the Shift (Windows) or Alt/Option (Mac) key and hit the restore button on iTunes and select the downloaded IPSW file.
Download iOS 4.2.9 for Verizon iPhone 4
Download iOS 4.2.9 for Verizon iPhone 4 (iPhone3,3_4.2.9_8E501_Restore.ipsw)
iPhone 4 GSM, iPod Touch and iPad users can download iOS 4.3.4.