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49. Cheat Sheets

49.1 How to Use These Cheat Sheets

Pehle mindset, mag tables. Cheat sheet = pocket map for what you already practised in earlier chapters. Samjla ka?

Print / revise rules (classroom):

  1. Blue column first – every Red-looking command has a defender note. Interview answers lead with control language.
  2. OWN IP only – rewrite example IPs to your host-only range before you type.
  3. One tool, one lab tick – do not “read all flags once”; type three commands on OWN VMs and tick.
  4. Ethics line every session – “Do I own this / have paper?” before Enter.
  5. Amazon Linux habit – prefer sudo yum and sudo service … start|stop|restart|reload|status. Ubuntu notes use apt where marked. Avoid day-to-day systemctl start (see Tip).
Red team (attacker) does Blue team (defender) detects / stops
Treats cheat sheet as exploit cookbook for random IPs Scope document; host-only lab; refuses illegal asks
Memorises flags with zero Blue story Revises command + meaning + detection / fix one-liner
Skips “ethics line” as soft text Says authorisation out loud before every scan session

Ravindra Bagale's Tip

Students print a cheat sheet and try nmap on cafe Wi-Fi as “practice”. That is a career and legal risk. Write OWN on the sheet. Rattling off flags ≠ being a hacker. A blank Blue column = incomplete revision. Remember this.

Lab

Print sections 49.2–49.5 (or copy into notebook). Highlight three Linux, three MySQL, three Nmap, three Metasploit lines you will type this week on host-only 192.168.56.x only. Write one Blue sentence under each highlight.

Extended teaching notes

Why this lesson matters

Use this lesson to strengthen systems you own: understand the risk, practise safely in a lab, then write and apply the fix.

Apply the fix across stacks

Same class of bug, same idea in every language.

Java / Spring Boot

Parameterise queries, encode output, CSRF tokens, limited Actuator, dependency scanning.

ASP.NET Core

EF Core / parameterised SQL, Razor encoding, HTTPS, Data Protection.

Node.js / Express

helmet, parameterised SQL, npm audit, avoid eval and shell concat.

Python / Django / Flask / FastAPI

ORM, autoescape, pip-audit, Bandit; never shell=True with user input.

PHP / Laravel

PDO/Eloquent, Blade escaping, composer audit.

Go / Ruby

database/sql placeholders / ActiveRecord; html/template / ERB escaping; govulncheck / Brakeman.

nginx / Apache / Tomcat

Hide versions, TLS, security headers, least-open ports.

MySQL / PostgreSQL / MongoDB / Redis

Private networks, auth on, least-privilege users, no 0.0.0.0/0.

AWS / Azure / GCP

Roles not long-lived keys, private data stores, cloud audit logs on.

Mini case study

Suppose we are on a purple-team exercise for an Indian mid-size company (sample data). Red notes a technique from this lesson against a lab clone. Blue must show the control that stops it, the log that would have fired, and the ticket that hardens production. That is the standard this course trains you for.

Defender's worksheet (do this today)

  1. Write the lesson title, date and the exact lab target you are allowed to use.
  2. List three owned systems (VMs, apps, or cloud accounts) where this lesson applies.
  3. Run one safe check from the lesson on a lab system only. Paste the command and output.
  4. Write a two-sentence fix you would give a teammate.
  5. Name one related public advisory (CERT-In, CISA, NVD, or a vendor bulletin) with its date.

Indian workplace (sample data)

Suppose we are a junior analyst at Infosys, TCS, Wipro or a fintech SOC in Bengaluru/Pune. Turn this lesson into one checklist item with an owner, a due date and a place to store evidence (ticket + screenshot).

Global practice

Compare your notes with OWASP, CIS Benchmarks, NIST CSF/IR guidance or a cloud Well-Architected security question. Write five lines on what overlaps.

Everyday analogy

Explain the risk and the fix to a family member without jargon. If they can repeat the warning, you understand it well enough to teach juniors.

Key terms

  • Control: a safeguard (patch, config, process, detection).
  • Finding: a weakness backed by evidence.
  • Remediation: the fix plus how you verified it.
  • Scope: systems you have written permission to touch.
  • Least privilege: only the access the task needs.
  • Defence in depth: several layers so one failure does not end the story.

Common mistakes

  • Skipping written permission "just for a quick scan".
  • Practising on hostel, office or public targets without authorisation.
  • Collecting tool output without writing the fix.
  • Copying attack steps onto production to "verify". Defenders verify with versions, configs and patches.
  • Publishing screenshots that contain secrets, cookies or internal hostnames.

Recap

  • Evidence, fix, owner, date.
  • Own lab only.
  • Fix > spectacle.