Agent Security Patterns#

An AI agent with tool access is a program that can read files, call APIs, execute code, and modify systems – driven by natural language input. Every classic security concern applies, plus new attack surfaces unique to LLM-powered systems. This article covers practical defenses, not theoretical risks.

Prompt Injection Defense#

Prompt injection is the most agent-specific security threat. An attacker embeds instructions in data the agent processes – a file, a web page, an API response – and the agent follows those instructions as if they came from the user.

PostgreSQL 15+ Permissions: Why Your Helm Deployment Cannot Create Tables#

Starting with PostgreSQL 15, only the database owner and superusers can create objects in the public schema by default. This breaks a common Helm pattern where you create a user, grant privileges, and expect it to create tables. The application connects fine but fails on its first CREATE TABLE.

The Symptom#

Your application pod logs show something like:

Error: permission denied for schema public

Or from an ORM like Mattermost’s: