Introduction

Chapter 11, "Windows I: Objects and the File System," explored general architectural issues that affect the security of Windows applications. It focused on developing an understanding of the Windows security model and its object-based architecture. Up to this point, however, you have looked at these components only in isolation from the rest of the system. To complete your understanding of Windows, you need to consider the interprocess communications (IPC) mechanisms Windows provides and how they affect application security.

IPC refers to the mechanisms for passing data (in a myriad of forms) between two related or unrelated processes. These processes can exist on the same machine or could be located on different machines that communicate across a network. Windows operating systems provide a wide variety of native IPC mechanisms, each with a rich feature set for controlling communication details and access controls. These mechanisms are used extensively to transmit data, apportion workloads, and signal events between processes on the same system or across a network.

Of course, all this capability comes at a price; communication mechanisms must expose some attack surface and open the potential for new vulnerabilities. In the most severe cases, Windows IPC vulnerabilities have allowed remote unauthenticated users to gain full administrative access to a vulnerable machine. This chapter examines several popular IPC mechanisms in Windows operating systems and explains how to apply what you have already learned to assess services using these IPC mechanisms.