Man-in-the-Browser

Definitions

Man-in-the-Browser is an attack technique in which an adversary modifies a browser session locally to alter transactions and observe content in real time. Defenders analyze it to understand prerequisites, affected trust boundaries, and likely telemetry, then reduce risk with layered controls such as validation, hardening, rate limits, segmentation, and high-quality logging for investigation and response.
In plain English: Man-in-the-Browser is a way attackers abuse systems or trust relationships, and defenders counter it with better design, validation, monitoring, and layered controls.
Example: "During the assessment, the team simulated Man-in-the-Browser against a staging service, confirmed the weakness with logs and telemetry, and then added tighter validation, safer defaults, and monitoring so the same technique would trigger an alert in production."