This Dell package contains a system BIOS update for Latitude 3420/3520 Systems . A BIOS firmware package is embedded on a small memory chip on the system board. It controls the keyboard, monitor, disk drives, and other devices. This update addresses the Dell Security Advisories (DSA). A security advisory is a statement when a security vulnerability impacts a product, and a remedy is available for the vulnerability. See Dell for more information: Security Advisories, Notices, and Resources