Lockdown: Dynamic Control-Flow Integrity
This addresses security for legacy systems vulnerable to code execution attacks, but it is incremental as it builds on existing CFI defenses.
The paper tackles the problem of memory corruption vulnerabilities in low-level language applications by introducing Lockdown, a dynamic Control-Flow Integrity (CFI) approach that protects binary-only executables and libraries, resulting in low performance overhead.
Applications written in low-level languages without type or memory safety are especially prone to memory corruption. Attackers gain code execution capabilities through such applications despite all currently deployed defenses by exploiting memory corruption vulnerabilities. Control-Flow Integrity (CFI) is a promising defense mechanism that restricts open control-flow transfers to a static set of well-known locations. We present Lockdown, an approach to dynamic CFI that protects legacy, binary-only executables and libraries. Lockdown 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 prototype implementation shows that dynamic CFI results in low performance overhead.