Apple today released iOS 4.2.7 Software Update which contains improvements and other bug fixes including the latest security updates.
Products compatible with this software update:
• iPhone 4 (CDMA model)
For information on the security content of this update, please visit this website: http://support.apple.com/kb/HT1222
This update is available via iTunes.
Apple releases iOS 4.3.2 for iPhone 4 (GSM), iPhone 3GS, iPads, and iPod touch models – April 14, 2011