2 posts tagged with "hardening"

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Part 1 of this series audited a live multi-agent box and found every network-exposure question worth asking. One line from that audit didn't get followed up: "the Postgres, ClickHouse and Redis behind Langfuse were published to 127.0.0.1 instead of the world — someone made a good decision there. Hold that thought."

Here's the other half of that thought: getting the network right says nothing about what happens after someone's already inside a container. If the process running in there is root, a compromise starts with the keys to the whole filesystem. So we checked — on the same box, the same Langfuse stack Part 1 already praised — whether "network correct" also meant "privilege correct." It didn't, for two of the six containers. Here's what fixing that actually looked like, including the part that broke.

You start with one agent. Then it needs a database. Then you add a second agent, a messaging bridge, an observability stack. Six months later a single WEC Instance is running five compose projects, twenty-something containers, and nobody remembers which ports are open to the world.

That's not a hypothetical — that's the box this tutorial was written on. So instead of theorizing, we probed it: can containers reach each other across stacks? Can they reach the databases? Is the firewall actually protecting anything?

Three of the answers surprised me. One of them was a database sitting there with no password. And the firewall — the firewall was lying.