A user needs to transfer some information from a work computer to a server. The user plugs a personal USB into the computer but is denied access to save information on the storage medium due to the…

Port security is a network switch feature that restricts which MAC addresses can communicate on a physical network port and does not apply to USB storage device access on an endpoint.

An access control list (ACL) governs permissions to network resources or firewall traffic rules and is not the mechanism used to block USB storage devices on an endpoint.

A Trojan horse is a type of malware disguised as legitimate software and is a threat, not a security control or policy enforcement mechanism.

DLP solutions enforce organizational policies that restrict how data can be copied, moved, or transmitted - including blocking writes to removable storage devices like personal USB drives. The scenario describes exactly this use case: a security policy automatically denying an action that could result in data leaving the corporate environment, which is the core function of DLP. The block is policy-driven and content/context-aware, not simply a network or port-level control.