When Memory Corruption Met Concurrency: Vulnerabilities in Concurrent Programs

Concurrent programs are widespread in modern systems. They make better use of processor resources but inevitably introduce a new set of problems in terms of reliability and security. Concurrency bugs usually lead to program crashes and unexpected behavior, and are an active research topic. From a security perspective, concurrency vulnerabilities are those that exhibit harmful behavior exclusively in concurrent executions. They can take place in a diverse range of environments, such as in operating system kernels, file system operations, or general-purpose multithreaded programs. A particular characteristic of concurrency is that it not only introduces new problems, but also enables traditional vulnerabilities to be triggered in concurrent-specific ways. Those that lead to dangerous security vulnerabilities usually cause memory corruption, a strong and flexible primitive for exploitation, and are known as concurrency memory corruption vulnerabilities. In this paper, we systematically analyze concurrency vulnerabilities in C and C++ programs, their exploitation and their detection, focusing on concurrency memory corruption vulnerabilities. We organize previous work on concurrency bug characteristics and detection, and highlight the differences in relation to vulnerabilities. Then, we examine the existence of concurrency vulnerabilities in real-world programs by searching the CVE database and point out a growing trend. Further, we analyze and compare existing detection approaches towards concurrency memory corruption.