Thinking Outside the Sandbox - Violating Trust Boundaries in Uncommon Ways

Presented at Black Hat USA 2014, Aug. 7, 2014, 11:45 a.m. (60 minutes).

Attacking the modern browser and its plugins is becoming harder. Vendors are employing numerous mitigation technologies to increase the cost of exploit development. An attacker is now forced to uncover multiple vulnerabilities to gain privileged-level code execution on his targets. First, an attacker needs to find a vulnerability, leak an address to get around ASLR, and bypass DEP to gain code execution within the renderer process. The attacker then needs to bypass the application sandbox to elevate his privileges, which will allow him to do something interesting. Our journey begins at the sandbox and investigates some of the more obscure techniques used to violate this trust boundary. What should you focus on when you are auditing a sandbox implementation? There are the traditional approaches: find a memory corruption vulnerability in IPC message handling, attack the kernel to get SYSTEM-level privilege escalation, or abuse shared memory regions. Sure, any of these will work but they may not be the easiest way. Our presentation will examine four bypass techniques successfully used in winning entries at this year's Pwn2Own contest. We will analyze the attack vector used, root causes, and possible fixes for each technique. These uncommon, yet highly effective, approaches have been used to bypass the most advanced application sandboxes in use today, and understanding them will provide a unique perspective for those working to find and verify such bypasses.

Presenters:

  • Brian Gorenc - Zero-Day Initiative, HP Security Research
    Brian Gorenc is the Manager of Vulnerability Research in HP's Security Research organization where his primary responsibility is running the world's largest vendor-agnostic bug bounty program, the Zero Day Initiative (ZDI). He's analyzed and performed root cause analysis on hundreds of zero-day vulnerabilities submitted by ZDI researchers from around the world. Brian is also responsible for organizing the ever-popular Pwn2Own hacking competitions. Brian's current research centers on discovering new vulnerabilities, analyzing attack techniques, and identifying vulnerability trends. His work has led to the discovery and remediation of numerous critical vulnerabilities in Microsoft, Oracle, Novell, HP, open-source software, SCADA systems, and embedded devices. He has also presented at numerous security conferences such as Black Hat, DEF CON, and RSA. Prior to joining HP, Brian worked for Lockheed Martin on the F-35 Joint Strike Fighter program where he led the development effort of the Information Assurance (IA) products in the JSF's mission planning environment. He has in-depth knowledge of software vulnerabilities, exploitation techniques, reverse engineering, and secure coding practices. Brian has a MS in Software Engineering from Southern Methodist University and a BS in Computer Engineering from Texas A&M University. He also holds several certifications including ISC2's CISSP and CSSLP.
  • Jasiel Spelman - Zero Day Initiative, HP Security Research
    Jasiel Spelman is a vulnerability analyst and exploit developer for the Zero Day Initiative (ZDI) program. His primary role involves performing root cause analysis on ZDI submissions to determine exploitability, followed by developing exploits for accepted cases. Prior to being part of ZDI, Jasiel was a member of the Digital Vaccine team where he wrote exploits for ZDI submissions, and helped develop the ReputationDV service from TippingPoint. Jasiel's focus started off in the networking world but then shifted to development until transitioning to security. He has a BA in Computer Science from the University of Texas at Austin.

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