Project 70: Client-Side Security Analysis

Module: Module 7: Wireless, Systems & Mobile Security  |  Level: Intermediate  | 
Primary tool: Browser DevTools  |  Estimated time: 75–120 minutes

Objective: Audit a page’s client-side security posture: CSP, mixed content, exposed source maps/secrets.

Free lab environment

PortSwigger Web Security Academy + OWASP Juice Shop — https://portswigger.net/web-security and https://owasp.org/www-project-juice-shop/

PortSwigger’s Web Security Academy is 100% free (no paid tier required) and gives you an isolated, disposable vulnerable lab instance for every topic. For projects that need a full application to explore end-to-end, run OWASP Juice Shop locally with `docker run -p 3000:3000 bkimminich/juice-shop` (free, open-source, built by OWASP specifically to be broken).

Lab workflow

  1. Open the lab environment (PortSwigger Web Security Academy or a site you own) and read the challenge description in full before touching anything.
  2. Using Browser DevTools, explore the application’s normal, intended behavior first — you cannot recognize an anomaly without a baseline.
  3. Attempt to audit a page’s client-side security posture: CSP, mixed content, exposed source maps/secrets, adjusting your input methodically (change one variable at a time) rather than guessing randomly.
  4. The moment you get a signal the technique is working, stop and capture evidence before pushing further — over-testing a confirmed finding wastes time and risk for no additional proof.
  5. Write the exact remediation for the specific code pattern involved — ‘sanitize input’ is not sufficient; name the actual fix (parameterization, encoding, allow-listing, etc.).
  6. If the lab platform offers a ‘solved’ confirmation, capture that as supporting evidence alongside your own screenshots.

Evidence & screenshot requirements

Submit the following with your report (see this module’s practical assignment for exact upload details):

  • DevTools’ Console/Network tab showing any CSP violation or mixed-content warning
  • your written list of any client-exposed secret or overly permissive CSP directive you found

Expected deliverable

A concise lab-report entry containing: scope/target, exact commands or payloads used, your key
observation, the required screenshots above, and — where applicable — the specific remediation for what
you found. Vague answers (“sanitize input”, “use a firewall”) without naming the exact mechanism will not
receive full credit.

Safety & authorization

Only test the specific free lab target named above, or infrastructure you personally own. Do not target
third-party systems, real user accounts, or production services without explicit written authorization.
Never deploy anything from this project outside an isolated lab environment.