Security

The council worked. One request went to Claude, Codex and Kimi, they answered independently, and nothing touched the lab without a human approval bound to a hash of the exact plan. It also lived entirely in a terminal, which meant that to approve a run I had to type a run id like hc-20260822-6fbfa5 and then re-type the original 350-character request verbatim, because resume rebuilds the context pack from it. Get one character wrong and you have quietly changed the inputs the agents were judged on. ...

I have three coding agents with access to this lab. Claude Code does most of the building. Codex reviews and runs the scans. Kimi audits. Until this week they had never exchanged a word — each got its own context, its own session, and its own chance to be confidently wrong with nobody checking. So I built a thing that makes them work one request together, and put a human approval gate in front of anything that changes the lab. ...

I run two coding agents against this lab. Codex found the problem and Claude Code fixed it, and keeping those two jobs in different hands turned out to be the most useful part of the whole exercise. The short version: a full vulnerability scan reported 2042 actionable findings — 46 critical, 764 high — and 1751 of them were in container images. Ten waves of updates later, the same scanner reports 1497 actionable, 21 critical, 570 high. ...

My homelab has picked up a lot of moving parts this year, and several of them are now LLMs. Claude Code runs natively on the box and does real work against real infrastructure — containers, reverse proxy config, monitoring, the lot. That’s genuinely useful. It also creates a trust problem I hadn’t had before. The problem is simple to state: the same agent that makes a change also writes the summary explaining why the change was safe. That’s convenient. It is not independent verification. If the agent quietly skips a validator and then reports “config validated”, I have no signal at all. The report is the evidence, and the thing that wrote the report is the thing being checked. ...

Two halves apt patches Debian. My homelab is not Debian — it’s about a dozen containers sitting on top of Debian. AdGuard, Authentik, Vaultwarden, Caddy, n8n, Greenbone, Homepage. apt will never once mention that Vaultwarden cut a release. So “keep the lab patched” is really two jobs: Debian packages — unattended-upgrades, already a solved problem, just needs scheduling and a report. Everything I actually run — nobody’s solved that for me. Containers only update when I decide to pull. This post is both halves. The first one taught me something uncomfortable about monitoring, so I’ll start there. ...

I wanted a DNS sinkhole in the lab — block ads, trackers, and adult content at the resolver instead of per-device. AdGuard Home is a single Go binary, so standing it up was maybe ten minutes. Then I spent the rest of the session learning that “point a device at the resolver” is a lie three times over. A Windows PC, an iPhone, and the lab host each route DNS somewhere I didn’t tell them to, for three completely different reasons. This is the write-up of finding all three. ...

I ended up with two VPNs into my homelab. WireGuard, running on my firewall, which I set up first. And Tailscale on my main server, which I added later so I could SSH in from a laptop without opening ports. Then I tried to use both from my phone and hit a wall. Phones only run one VPN at a time This isn’t a bug or a conflict between the two apps. iOS and Android both allow exactly one active VPN tunnel, full stop. It’s an OS-level restriction. ...

I wanted a real vulnerability scanner in the lab — something that port-scans a host, throws a big pile of network vulnerability tests at it, and tells me what to fix by severity. OpenVAS (now Greenbone Community Edition) is the obvious choice, and it ships as a Docker stack. This is the honest write-up: the install, the three separate things that broke, one of which was my own fault, and what the scanner actually found when I pointed it at my own box. Nothing here is polished — I got a couple of things wrong along the way and I’m leaving those in, because that’s where the useful bits are. ...

A while back I hardened this Debian VM by hand — patched it, cut the attack surface, put a default-deny host firewall in front of it, sandboxed the custom services. I audited my own box and fixed the drift I found. The problem with auditing your own box is that you grade your own homework. You check the things you already think to check. So this time I handed the job to something that has no idea what I meant to do and only reports what’s actually there: Lynis, the system-auditing tool from CISOfy. It ran 274 tests and gave the VM a hardening index of 68 / 100. ...

I had dashboards showing me numbers — CPU, memory, network throughput. What I didn’t have was any way to answer “what actually happened?” When did someone try to log in? What did the firewall block? Those answers live in logs, and my logs were scattered across machines, unread. This post is how I pulled them into one searchable place. That’s a SIEM — Security Information and Event Management — and you can build a simple one at home. ...

Bringing pfSense’s admin login into Authentik with MFA — via RADIUS, which turned out to be broken upstream, and then via LDAP, which wasn’t. This is as much about how you prove a bug isn’t yours as it is about the build. Stack: Authentik · pfSense · Docker · LDAP · RADIUS 1. Purpose With an identity provider already running and Grafana logging in through it, the obvious next question was: how far does this go? ...

Deploying Authentik as a self-hosted identity provider, and wiring Grafana into it with OIDC — so a service that has never heard of MFA suddenly requires it. Stack: Authentik · Caddy · Grafana · Docker · Debian 1. Purpose Every self-hosted service arrives with its own login. Ten services means ten accounts, ten passwords, and ten places to forget to enable MFA. Worse, some services have no authentication at all and just quietly assume nobody hostile is on your network. ...

Building a self-hosted password vault with a genuinely trusted TLS certificate and zero inbound ports open to the internet — and the four-layer debugging session that stood between me and a working container. Stack: Debian 13 · Docker · Caddy (custom build) · Vaultwarden · pfSense · WireGuard · DuckDNS 1. Purpose Self-hosted services are easy to do badly. It’s trivial to run a container, forward a port, click through a certificate warning, and call it done — and end up with something less secure than the cloud service you replaced. ...

The blog you’re reading just moved house. Same content, same build, the same Cloudflare Pages underneath — but the address on the door changed from billalrehmani.pages.dev to a domain that’s actually mine: billsblog.dev. Why bother — it already worked billalrehmani.pages.dev was fine. It served over HTTPS, it was fast, it was free. But pages.dev is Cloudflare’s namespace, not mine. For a portfolio I link from LinkedIn and want people to remember, “billalrehmani-dot-pages-dot-dev” is a mouthful and a borrowed address. Owning the domain means owning the identity — and, as it turned out, a bit more control over the security posture too. ...

A flat network trusts every device on it equally. A smart plug, a guest’s phone, and the machine holding my important data all share one space — so if any one of them is compromised, the attacker can reach the rest. Network segmentation breaks that flat space into separate zones and controls what may cross between them, shrinking the blast radius of any single compromise. I wanted to build that properly — VLANs and a firewall — on VMware Workstation with pfSense CE, and design three zones at deliberately different trust levels: ...

My lab is deliberately isolated — an automation VM (CLAUDDEB) sits behind a virtual pfSense firewall on a segment (10.10.0.0/24) that my home network can’t reach. That isolation is great until you’re out of the house and want to check your Grafana dashboards, which only listen inside that segment. I already use Tailscale for casual remote access, and I’ll be honest up front: for pure convenience, Tailscale wins — it punches through NAT automatically with zero firewall work. But this project wasn’t about convenience. It was about building the thing Tailscale is made of. Tailscale is WireGuard under the hood; hand-rolling raw WireGuard on pfSense teaches you how VPNs actually work — keys, peers, routing, firewall rules, NAT — at a level the managed tool deliberately hides. So I built it from scratch, kept Tailscale as my daily driver, and got a genuinely brutal debugging lesson in the process. ...

My Debian automation VM already sits behind a pfSense firewall with egress containment — it can reach the internet but not my home network. So why harden the VM itself? Because “behind a firewall” is doing less work than it sounds. Two paths reach into the VM without ever crossing pfSense, and an honest audit of my own box turned up drift I didn’t expect. This is the write-up: what the audit found, what I changed, and the systemd sandbox mistake that quietly broke a service. ...

I run my Claude Code work inside a Debian 13 VM (CLAUDDEB) on VMware Workstation Pro 17.6.4, with a pfSense 2.8.1 VM in front of it as a virtual router and firewall. pfSense exists in this setup for containment: if something on the Debian VM misbehaves — a prompt injection, a compromised dependency — it must not be able to reach my PC, my router’s admin page, or anything else on the home network. ...

This is a small home network — one router, a handful of devices. The point wasn’t complexity; it was applying the same discipline you would to a small office or lab environment. Treated that way, it doubles as practical study for Network+ and Security+. The router is an Arcadyan HWG2025 — the NBN-issued unit, Wi-Fi 7 with MLO, around 500 Mb down. An ISP router doesn’t give you much room to move, but it gives you enough to do this properly. ...