USB Protection is a security control that limits what can happen over the USB port when a phone is locked. Instead of treating a cable connection as harmless, the operating system can block data access, accessory interaction, or other sensitive USB functions until the user authenticates. This reduces the attack surface exposed by lost devices, shared charging points, and brief physical access.
In real attacks, USB ports can be abused through malicious accessories, modified charging stations, or forensic-style tools that try to extract data or trigger hidden behaviors. USB Protection helps stop those paths by making the locked state less useful to an attacker. It is commonly paired with stronger device policies, authentication checks, and logging, so defenders can both prevent unauthorized access and better understand suspicious connection attempts.