h4ckers.infoSearch terms

Knowledge base · h4ckers.info

h4ckers.info — Learn to break things, so you can build them stronger.

A free, no-nonsense reference for security learners and capture-the-flag players. Curated tactics, a searchable glossary, and structured guides across five disciplines — written by practitioners, for the field.

Start the guide Browse the tracks

Recon, in practice

Every engagement starts the same way: enumerate, then narrow. Here's a two-command opener — map the services, then fuzz for what shouldn't be there.

recon — zsh — 80×24
analyst@h4ckers:~/ctf$ nmap -sV --top-ports 100 target.lab
Starting scan...
PORT     STATE  SERVICE   VERSION
22/tcp   open   ssh       OpenSSH 8.9
80/tcp   open   http      nginx 1.24.0
443/tcp  open   ssl/http  nginx 1.24.0
analyst@h4ckers:~/ctf$ ffuf -u https://target.lab/FUZZ -w words.txt
/admin               [Status: 302]
/.git                [Status: 200]  # jackpot
analyst@h4ckers:~/ctf$ _▋

What this is

No fluff, no autoplay video, no paywall — just the working knowledge you reach for mid-challenge, organized the way you actually think.

33+
Glossary terms
5
Skill tracks
100%
Free & offline
0
Trackers
  • Structured by discipline. Five clean tracks, each with a mental model, curated tactics, and the tools pros run.
  • Instant glossary search. A live client-side filter over every term — type a few letters, zero round trips.
  • Ethics built in. Every technique is framed for authorized testing and defense.
  • Offline by design. No CDNs, no third-party fonts, no telemetry — loads cold on a flight or in an air-gapped lab.

Five disciplines, one model

Pick a lane or rotate through all of them. Each track answers the same question: where does trust break, and how do you prove it?

Forget what %n does at 2am?

The searchable glossary defines the acronyms and attacks you meet in every challenge — with a concrete example for each. Filter the entire list live, right in your browser.

SQL InjectionSQLiInserting attacker-controlled SQL into a query the application sends to its database, letting yo…
Cross-Site ScriptingXSSGetting a victim's browser to execute attacker-supplied JavaScript in the context of a trusted s…
Server-Side Request ForgerySSRFCoercing a server into making HTTP requests on your behalf — often to internal services, cloud m…
Cross-Site Request ForgeryCSRFTricking an authenticated user's browser into submitting an unwanted state-changing request, abu…
Open the glossary

One rule above all

Everything here is for systems you own or are explicitly authorized to test. Security knowledge is a tool — point it at the right targets. Practice on the legal labs we link, report what you find responsibly, and leave every system better than you found it.

Read the ethics primer