Lockdown: Dynamic Control-Flow Integrity Mathias

Applications written in low-level languages without type or memory safety are especially prone to memory corruption. Attackers gain code execution capabilities through such ap-plications despite all currently deployed defenses by exploit-ing memory corruption vulnerabilities. Control-Flow In-tegrity (CFI) is a promising defense mechanism that restricts open control-flow transfers to a static set of well-known lo-cations. We present Lockdown, an approach to dynamic CFI that protects legacy, binary-only executables and libraries. Lock-down adaptively learns the control-flow graph of a running process using information from a trusted dynamic loader. The sandbox component of Lockdown restricts interactions between different shared objects to imported and exported functions by enforcing fine-grained CFI checks. Our proto-type implementation shows that dynamic CFI results in low performance overhead. 1