A browser proxy is an intermediary that sends web traffic through a defined path before it reaches the destination site. It can be used to inspect requests, enforce policy, log activity, block unsafe content, or make browser sessions follow an approved routing rule. In managed environments, a proxy may be controlled by an extension, agent, or enterprise browser policy.
Browser proxies matter in cyber security because they sit in the trust path between the user and the internet. If an attacker can change proxy settings, they may redirect traffic, intercept credentials, weaken monitoring, or send sensitive browsing data to an untrusted server. Defenders use proxies to filter and observe traffic, but they also need to protect proxy configuration, validate who can change it, and watch for unexpected PAC file updates, redirects, or extension-driven proxy changes. In privileged browsing, proxy control is especially sensitive because it can affect administrative sessions and recorded activity.