Cybersecurity, learned like a practitioner.
24 learning paths · 398 modules live · every lesson written by someone who has shipped the control or run the engagement. Free to start.
Latest modules
Most recent practitioner playbooks across every track. Filter by topic, level, or search in the sidebar.
Cleartext Is Forever
An adversary records your encrypted traffic today. Stores it. Years later, quantum computer breaks the key exchange. Decrypts. This isn’t hypothetical. Nation-state adversaries have been recording for years. Long-lifespan secrets — IP, state secrets, banking credentials — are exposed even when transmitted over modern TLS today. The mindset: data with multi-decade sensitivity needs post-quantum protection […]
Browser Origin Boundaries
Same-Origin Policy is the bedrock of web security. But “origin” has nuances: scheme matters, port matters, path doesn’t. Subdomains aren’t same-origin (they’re same-site, different concept). CORS is opt-in cross-origin. It carries credentials only with explicit allow. Access-Control-Allow-Origin: * with credentials is invalid. Many implementations get this wrong. postMessage crosses origins by design. Receiver must validate […]
The Cookie Confusion Cascade
Cookies are the most-misunderstood browser feature. Domain attribute, path, SameSite, Secure, HttpOnly, Partitioned — each affects when the browser sends the cookie. Combinations produce surprising behaviour. Examples that catch defenders off guard: cookie set on parent domain visible to subdomain (intentional, abuseable); SameSite=Lax allows top-level navigation cookies (CSRF window); Partitioned cookies behave differently per top-level […]
Authentication vs Authorization Split
Authentication: who are you. Authorization: what can you do. Most security education conflates them. Most bugs live in the gap. An authenticated user is not authorized for everything they ask. Authorization is per-resource, per-action, often per-attribute. IDOR exists because authn is correct but authz is missing. The mindset: at every endpoint, two questions: “is this […]
Why Validation at Multiple Layers
Defence in depth is a phrase. Multi-layer validation is its application. Client-side validation catches user mistakes. Edge validation (WAF) catches bulk attacks. Server-side validation enforces business rules. Database constraints catch the rest. Each catches what the others miss. Skip a layer = bypass that layer’s coverage entirely. The mistake: assuming “the WAF catches it” or […]
State Machines Have More Edges Than You Think
Every web app is a state machine. Order = pending → paid → shipped → delivered. State transitions have rules. The rules have gaps. Attackers enumerate edges adversarially: can I go from pending to delivered, skipping paid? Can I cancel after shipped? Can I trigger paid → paid (double payment processing)? The mindset: draw the […]
The Three Types of Web Sessions
“Session” is overloaded: browser session (open tabs), server session (data keyed by session ID), application session (the user’s logical workflow). Each has different lifetime; each has different invalidation rules. The bug pattern: developer thinks “user logged out, session ended.” Browser session ended. Server session may persist. JWT may still be valid. OAuth refresh token still […]
Why HTTP Headers Are Programmable Trust
Application code routinely trusts HTTP headers. X-Forwarded-For for client IP. Host for routing. Origin for CORS. Each is attacker-controllable in some path. If your code does if (request.headers["X-Admin-Override"] == "true"), you’ve created a backdoor. If your code trusts X-Forwarded-For without validating the immediate peer, you’ve created an IP-spoofing primitive. The mindset: each header your code […]
CDN as Attack Surface
CDN was once a passive cache. Now: edge functions, header rewriting, cache key manipulation, custom routing. Each is a new attack surface. Cache poisoning, cache deception, edge-function privilege escalation, header injection between CDN and origin — all bug classes that didn’t exist when CDN was just static-asset cache. The mindset: list every CDN feature you […]
The 5 Trust Boundaries in Every Web App
Trust boundaries are where one component trusts data from another. Each crossing is a place to validate. Most apps have at least 5: Browser to server (the obvious one — input validation) Server to database (parameterised queries) Server to upstream API (output validation, response-content trust) Server to cache (cache-key collisions, deserialisation) Server to message queue […]
Practitioners who've
shipped the controls.
Every module is written by someone who has built the defence or run the engagement. No repackaged tutorials, no generic theory.
Why learn here
Practitioner-written.
Each lesson is authored by someone who has shipped the control or run the engagement in production.
Quiz after every module.
20+ questions with explanations. 70%+ to mark complete. Unlimited retries.
Progress tracked.
Completions, scores and streaks saved automatically. Resume exactly where you left off.
India-priced.
Start free. ₹499/mo for intermediate. ₹4,999/yr for advanced. No hidden fees, ever.