25. Wireless Security
Chala mitrano, aaj Wi-Fi cha vishay. Wi-Fi cha signal bhinti palikade, road paryant jato – mhanje tumcha data hawet aahe. Mhanunach Wi-Fi chi suraksha itki mahatvachi. Aaj aapan shiku Wi-Fi kase surakshit hote (WEP, WPA, WPA2, WPA3), attacker kay karto, ani – sarvat mahatvacha – tumcha swatahcha Wi-Fi kasa surakshit thevaycha. Ek goshta ekdum pakki: he sagle fakt tumchya swatahchya Wi-Fi var. Dusryachya Wi-Fi var he karne gunha aahe, thet turungat javnara. Samjla ka? Chala!
What you will learn in this chapter
- How Wi-Fi security evolved: WEP, WPA, WPA2, WPA3
- Monitor mode and the Aircrack-ng suite (concept and commands)
- How a WPA2 handshake capture and offline crack works, and why a strong passphrase stops it
- Evil twin and deauth attacks, in concept
- Securing your own Wi-Fi: WPA3/WPA2, strong passphrase, WPS off, guest network, router hardening
Lab scope for this whole chapter
Test only your own Wi-Fi router, one you fully control. Capturing handshakes, deauthenticating clients, or cracking any other network is a crime under the IT Act (sections 43 and 66). Even "just checking" a neighbour's Wi-Fi is illegal.
Concepts in this chapter
- 25.1Wi-Fi Security Standards
- 25.2Monitor Mode and the Aircrack-ng Suite
- 25.3WPA2 Handshake Capture and Offline Cracking
- 25.4Evil Twin and Deauth Attacks (Concept)
- 25.5Securing Your Own Wi-Fi
- 25.6Red vs Blue, Project and Real Incidents
The chapter recap is at the end of the last concept page.
Chapter 25: Wireless security — practice tasks
Open chapter lessons · Full guided lab: harden home wifi router wpa3 wps off (not repeated here)
25.1 Audit your home Wi-Fi settings
EasyITWhy: Home routers are often left on WPA2/WPS.
What: Check your own router admin page.
How:
- Log in to your gateway (often 192.168.0.1 or 192.168.1.1).
- Note encryption: WPA3 / WPA2 / WEP / Open.
- Check if WPS is on.
Expected output: WPA3 or WPA2-AES; WPS Off.
Hint
Change the default admin password too.
Answer / how to check
- Screenshot or write the settings.
25.2 Separate guest Wi-Fi
EasyRetailWhy: Guests must not reach shop POS devices.
What: Turn on the guest network on your own router.
How:
- Enable Guest Wi-Fi.
- Confirm guest clients cannot ping the main LAN.
- Put only guest phones on it.
Expected output: Guest IP in a different subnet; LAN ping fails.
Hint
Many routers call this AP isolation.
Answer / how to check
- POS/PC still on main Wi-Fi.
25.3 WEP vs WPA2 (paper)
EasyBankingWhy: Old standards are broken.
What: Mark each standard Safe or Replace.
Data file: wifi.csv
| Standard |
|---|
| WEP |
| WPA-TKIP |
| WPA2-AES |
| WPA3 |
About this file: Made-up list of Wi-Fi standards. Each row is one standard to judge.
How:
- Read the data file.
- Mark each row.
Expected output: WEP Replace; WPA-TKIP Replace; WPA2-AES Keep; WPA3 Keep.
Hint
WPS is a separate risk — turn it off.
Answer / how to check
- Only WPA2-AES and WPA3 are Keep.
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)
- Write the lesson title, date and the exact lab target you are allowed to use.
- List three owned systems (VMs, apps, or cloud accounts) where this lesson applies.
- Run one safe check from the lesson on a lab system only. Paste the command and output.
- Write a two-sentence fix you would give a teammate.
- 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.