Over the years, ring-0 vulnerabilities in mobile devices are becoming increasingly difficult to find and exploit. Attackers and defenders alike must find new attack vectors, as well as develop research tools to expedite the research process and increase coverage. One significant challenge is a more confining sandbox. While vendors usually put less emphasis on the security of mechanisms which are not operable from within the sandbox, sandboxing applications appropriately is not always that easy, and even when done correctly – might not be good enough.
This talk is a real-world journey of finding, we will be uncovering a deeply buried vulnerability in the iOS kernelcache. The vulnerability, which is hidden within the video-decoder driver, can be triggered by processing maliciously crafted codec frames. The driver is normally not accessible to the standard application. This vulnerability, however, is still exploitable from within a sandboxed process or application. During this talk, concepts, tools and methods of work will be given: from initial search till getting familiar with a complete closed-source environment, as well as a real-world example of finding “sandbox-restrictive” vulnerabilities and exploiting them from the most narrowed context nevertheless. We’ll also see how to start working on infrastructure and ideas for helping with closed-source kernel research. Additionally, We’ll talk about how zero-click exploits could utilize this attack vector for privilege escalations and why PAC makes it a bit more complicated to exploit it.
Additionally, We’ll talk about how zero-click exploits could utilize this attack vector for privilege escalations and why PAC makes it a bit more complicated to exploit it.