A DSN, or Data Source Name, is a saved connection profile used by database clients, BI tools, and drivers. It typically stores the target server, database name, driver type, authentication method, and sometimes user-specific settings such as ports or timeouts. In practice, a DSN tells an application how to reach a data source without hardcoding those details in every query or script.
In cyber security, DSNs matter because they often contain sensitive connection metadata and may point to systems with valuable data. If an attacker gains access to a workstation, server, or configuration store, a DSN can reveal where to connect and how the application authenticates. Weakly protected DSNs can also enable credential theft, unauthorized database access, or lateral movement through reporting and integration layers. Defenders treat DSNs as sensitive configuration, restrict who can read or edit them, and review them during migrations and incident response.