SANDBOXING AND ISOLATION FOR SAFETY

NETWORK EGRESS CONTROLS Egress means traffic leaving a system. Network egress controls limit what the agent can reach. The strongest approach is an allow-list, a short list of approved destinations, with everything else blocked. If an attacker tricks an agent into sending stolen data outward, as described in Chapter 38, an allow-list stops the message because the attacker's address is not on it. Some tools need no network at all, and for those, the best setting is no network access. RESOURCE LIMITS Resource limits cap how much memory, processor time, disk space, and running time a task may use. They prevent accidents, such as an endless loop that eats all the memory. They also limit abuse, such as a malicious program that tries to overload shared hardware. A limit might allow two gigabytes of memory and half of one processor core, and kill the task if it runs too long. These limits work hand in hand with the budgets in Chapter 25.