Author(s): Wilson Lian, Hovav Shacham, Stefan Savage

Download: Paper (PDF)

Date: 7 Feb 2015

Document Type: Briefing Papers

Additional Documents: Slides

Associated Event: NDSS Symposium 2015


In the face of widespread DEP and ASLR deployment, JIT spraying brings together the best of code injection and code reuse attacks to defeat both defenses. However, to date, JIT spraying has been an x86-only attack thanks to its reliance on variable-length, unaligned instructions. In this paper, we finally extend JIT spraying to a RISC architecture by introducing a novel technique called gadget chaining, whereby high level code invokes short sequences of unintended and intended instructions called gadgets just like a function call. We demonstrate gadget chaining in an end-to-end JIT spraying attack against WebKit’s JavaScriptCore JS engine on ARM and found that existing JIT spray mitigations that were sufficient against the x86 version of the JIT spraying attack fall short in the face of gadget chaining.