Ravindra BagaleCourses & study guides मराठी Track your progress

45. Practice Exercises with Hints

45.7 OWASP Top 10 – Fix What You Break (DVWA / Juice)

By Last updated:

SQLi, XSS, IDOR, command injection, SSRF – break on OWN DVWA/Juice, then fix and re-verify.

Exercise Task Hint
E1 DVWA SQLi low: prove injection, then patch with prepared statement sketch Own VM only; never sqlmap a live shop
E2 Reflected XSS: alert proof → output encoding + CSP note Encoding context matters (HTML vs attr)
E3 IDOR: change id= to another user in lab app → fix authZ check Server-side ownership check every request
E4 Command injection on ping field (DVWA) → allow-list args / no shell Never pass user input to shell
E5 SSRF idea: why cloud metadata is juicy; IMDSv2 as fix theme Cap One lesson; block link-local from app where possible
Red team (attacker) does Blue team (defender) detects / stops
SQLi / XSS / IDOR on OWN Juice / DVWA Prepared statements; encoding+CSP; authZ; allow-lists
Chains SSRF toward metadata IMDSv2; egress controls; least-privilege role

Ravindra Bagale's Tip

Students screenshot alert(1) and stop. The interview wants the fix. Break → Fix → Re-verify. Remember this.

Lab

OWN DVWA: set security low → SQLi module → capture proof → raise to high / apply prepared statement on your fork → prove payload fails. Two screenshots in notes.

Extended teaching notes

Why this lesson matters

Web flaws stay in the OWASP Top 10 because real apps still ship them. Your job is not to collect tool screenshots. It is to prevent and fix the class of bug on systems you own.

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.

Real examples

Global: injection and XSS still appear in breach reports and bug bounties every year. Indian company (sample): a Bengaluru SaaS team maps each OWASP item to a CI check or a code-review question so new code cannot silently reintroduce it.

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.