Pro PHP Security: From Application Security Principles to the Implementation of XSS Defenses, Second Edition

C H A P T E R  13

Securing Unix

Filesystem permissions are the fundamental means of controlling users' access to operating system resources. We will therefore begin with a discussion of Unix's filesystem and its permissions. Although some of this material may seem elementary to system administrators and experienced users, it is absolutely essential to a thorough understanding of controlling security by managing filesystem permissions.