APPLE-SA-2010-11-22-1 iOS 4.2 for iPhone, iPod Touch, iPad

http://support.apple.com/kb/HT4456

Apple has released over 80 patches in its latest update of iOS, the
operating system for its iPhone, iPod Touch, iPad devices.
Vulnerabilities mitigated in this release include: arbitrary code
execution, unexpected application termination and unexpected system
shutdown.

It is recommended that users of these devices update to the latest
version of iOS to avoid exploitation.

Thanks,
Brian