The Application Sandbox has been updated to enforce proper access restrictions between application sandboxes. This could lead to the disclosure of sensitive information. FreeType vulnerabilities have been closed.
Changes have also been made to improve security with the iPhone’s network connectivity. mDNSResponder has been updated to reduce susceptibility to DNS cache poisoning. TCP initial sequence numbers are now randomly generated, to thwart remote attackers from spoofing TCP connections.
The Passcode Lock feature is used to keep users from making accessing the iPhone without entering a multi-digit code. That feature could be thwarted thanks to an exploit involving the handling of emergency calls; that has been corrected. security in iPhone 2.1, Senate bill 1738, protect our children act