The iPhone user land is locked down very tightly by kernel level protections. Therefore any sophisticated attack has to include a kernel exploit in order to completely compromise the device. Because of this our previous session titled "Targeting the iOS Kernel" already discussed how to reverse the iOS kernel in order to find kernel security vulnerabilities. Exploitation of iOS kernel vulnerabilities has not been discussed yet.
This session will introduce the audience to kernel level exploitation of iPhones. With the help of previously disclosed kernel vulnerabilities the exploitation of uninitialized kernel variables, kernel stack buffer overflows, out of bound writes and kernel heap buffer overflows will be discussed.
Furthermore the kernel patches applied by iPhone jailbreaks will be discussed in order to understand how certain security features are deactivated. A tool will be released that allows to selectively de-activate some of these kernel patches for more realistic exploit tests.
Stefan Esser is best known in the security community as the PHP security guy. Since he became a PHP core developer in 2002 he devoted a lot of time to PHP and PHP application vulnerability research. However in his early days he released lots of advisories about vulnerabilities in software like CVS, Samba, OpenBSD or Internet Explorer. In 2003 he was the first to boot Linux directly from the hard disk of an unmodified XBOX through a buffer overflow in the XBOX font loader. In 2004 he founded the Hardened-PHP Project to develop a more secure version of PHP, known as Hardened-PHP, which evolved into the Suhosin PHP Security System in 2006. Since 2007 he works as head of research and development for the German web application company SektionEins GmbH that he cofounded.