Black Hat USA 2012: Owning Firefox's Heap
Continuing our work on jemalloc exploitation, myself and Chariton Karamitas (intern at Census, Inc) are presenting “Owning Firefox’s Heap” at Black Hat USA 2012. This presentation extends our recently published Phrack paper by focusing specifically on the most widely used jemalloc application, namely the Mozilla Firefox web browser.
The abstract of our talk will give you a good preview of the content:
jemalloc is a userland memory allocator that is being increasingly adopted by software projects as a high performance heap manager. It is used in Mozilla Firefox for the Windows, Mac OS X and Linux platforms, and as the default system allocator on the FreeBSD and NetBSD operating systems. Facebook also uses jemalloc in various components to handle the load of its web services. However, despite such widespread use, there is no work on the exploitation of jemalloc.
Our research addresses this. We will begin by examining the architecture of the jemalloc heap manager and its internal concepts, while focusing on identifying possible attack vectors. jemalloc does not utilize concepts such as ‘unlinking’ or ‘frontlinking’ that have been used extensively in the past to undermine the security of other allocators. Therefore, we will develop novel exploitation approaches and primitives that can be used to attack jemalloc heap corruption vulnerabilities. As a case study, we will investigate Mozilla Firefox and demonstrate the impact of our developed exploitation primitives on the browser’s heap. In order to aid the researchers willing to continue our work, we will also release our jemalloc debugging tool belt.