Less than two weeks ago, Apple released an update to iOS 4.3.4 to address the security loophole found with downloading PDFs as well as to block the JailBreakMe tool for unlocking iPhones. Today the company has released yet another update bringing iOS on GSM i-devices up to version 4.3.5 to fix some additional security concerns.
iOS 4.3.5 is a small update that seems to address only a security issue pertaining to certificate validation. The update document reveals that previously, an attacker with a privileged network position could capture or modify data in sessions even protected by SSL/TLS. Other possible attacks could be launched via X.509 certificate validation, hence the update also improves validation of X.509 certificate chains.
The 4.3.5 update is available to the GSM iPhone 4, iPhone 3GS, both versions of the iPad, and the third- and fourth-generation iPod touch, whereas the CDMA iPhone gets its own version of 4.2.10. You can get the update by plugging your iOS device into iTunes and clicking on "Check for Update."