Type of Publication: Article in Collected Edition

Just-In-Time Code Reuse: The More Things Change, the More They Stay the Same

Author(s):

Snow, Kevin; Davi, Lucas; Dmitrienko, Alexandra; Liebchen, Christopher; Monrose, Fabian; Sadeghi, Ahmad-Reza

Title of Anthology:

Black Hat USA

Publication Date:

2013

Link to complete version:

https://media.blackhat.com/us-13/US-13-Snow-Just-In-Time-Code-Reuse-Slides.pdf

Citation:

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Abstract

Fine-grained address space layout randomization (ASLR) has recently been proposed as a method of efficiently mitigating runtime attacks. In this presentation, we introduce the design and implementation of a framework based on a novel attack strategy, dubbed just-in-time code reuse, which both undermines the benefits of fine-grained ASLR and greatly enhances the ease of exploit development on today’s platforms that combine standard ASLR and DEP (e.g. Windows 8). Specifically, we derail the assumptions embodied in fine-grained ASLR by exploiting the ability to repeatedly abuse a memory disclosure to map an application’s memory layout on-the-fly, dynamically discover API functions and gadgets, and JIT-compile a target program using those gadgets - all within a script environment at the time an exploit is launched. We demonstrate the power of our framework by using it in conjunction with a real-world exploit against Internet Explorer, show its effectiveness in Windows 8, and also provide extensive evaluations that demonstrate the practicality of just-in-time code reuse attacks. Our findings suggest that fine-grained ASLR may not be as promising as first thought.