Data Bricklaying Diary

Oct 23, 2026 · Information Security

Why External Content Must Not Override Agent Permissions: Defending Against Indirect Prompt Injection

This article analyzes how AI agents can be manipulated via indirect prompt injection hidden in external materials, and proposes a layered defense: distinguish source from authority, validate every execution step, bind confirmations to specific actions, and test with adversarial scenarios to ensure boundaries hold without breaking legitimate tasks.