Speaker: Donghai Tian Title: Integrating Offline Analysis and Online Protection to Defeat Buffer Overflow Attacks Abstract: Nowadays Buffer overflow attacks are still recognized as one of the most severe threats in software security, although they have been comprehensively studied for more than 25 years. Previous solutions suffer from limitations in that: 1) Some methods based on compiler extensions have limited practicality because they need to access source code; 2) Other methods that need to modify some aspects of the operating system or hardware require much deployment effort; 3) Almost all methods are unable to deploy a runtime protection for programs that cannot afford to restart. In this paper, we propose PHUKO, an on-thefly buffer overflow prevention system which leverages virtualization technology. PHUKO offers the protected program a fully transparent environment and an easy deployment without the need to restart the program. Generally, the working process of PHUKO can be divided into two stages. First, we utilize static binary analysis to identify the instructions offline which are the entries of vulnerable functions. Second, by combining virtual machine introspection and online patching, PHUKO instruments the protected running program on-the-fly with memory safety enforcement. The experiments show that our system can defend against realistic buffer overflow attacks effectively with a moderate performance overhead (e.g., around 10% performance overhead for Apache web server).