GOLDEN CAGE

Nobody’s perfect – and this is particularly true of software. Any non-trivial application will have its fair share of programming errors. Intruders exploit these errors, taking control of the software, and making the program do things the developer never envisaged. The situation starts to become critical if the application has privileges that are different from the privileges of the attacker. For example, the ping command requires root privileges in order to send the special packet formats that it needs. But it is theoretically possible for the process to misuse its root privileges to cause all kinds of trouble. Although ping is a well-behaved program, an attacker capable of hijacking the tool would have unrestricted access to the rest of the system.