JSFoo Chennai 2020

JSFoo Chennai 2020

On component architecture, performance, security for front-end, and emerging trends

Riyaz Walikar


Captain Marvellous JavaScript - A look at how hackers use JS

Submitted Jan 16, 2020

The modern web would be grossly incomplete without JavaScript. While the dev world is using JS to build more user friendly, experience rich, responsive and fast web applications, hackers have been using JavaScript on a parallel trail using the same programming principles as the devs to break implmentations, attack users and servers alike.

In this very “informally fun” (TM) talk, filled with examples and demos, we will see how hackers (mis)use the constructs available within JavaScript/ECMAScript to go beyond XSS and automate vulnerability discovery, attack seemingly secure endpoints, exploit weaknesses in implementation and break user trust for profit and for fun.

The key takeways for attendees from this talk would be:
- Understanding how attackers see and use JavaScript
- Introduction to attacks and techniques/usage of JS beyond the standard XSS
- How JavaScript can be used as a powerful weapon in discovery and exploitation of vulnerabilities


  • Introduction to the talk
  • JavaScript and XSS: Is that it?
    • Why is XSS bad anyways?
    • I’ve Got No BeEF With You
      • Demo of a real world account and browser compromise
  • Mutation XSS
    • Abusing browsers’ code normalisation against them
  • Server Side JS attacks
    • The perils of insecure templating
    • Server Side JS injection
      • Remote Code Execution
  • JS and Desktop Applications
    • Mixing Desktop Clients and JavaScript (WCGW)
      • Case Study of
        • Code Execution using JavaScript in a Desktop Client
        • Remote Code Execution in a JavaScript Desktop App
        • HTML/JS Injection in a popular messaging client
  • Breaking filters and Web Application Firewalls
    • JS weirdness
    • Twisted XSS payloads
  • Malware, JavaScript and obfuscation
    • Case Study 1
    • Case Study 2
  • Using JavaScript to Fuzz browsers
    • JS fuzzing engines
    • Browser crashes and the $$$
  • Session Hijacking using ActionScript and Flash
    • Weaponising ActionScript for account takeovers
  • Attacking Network Devices using JavaScript
    • Taking over the DNS of a local home router from the Internet
  • Closing notes
  • The End / Q&A


  • Projector
  • Enthusiastic Audience

Speaker bio

Riyaz Walikar currently heads the Security Research Team at Appsecco. His team primarily works on identifying vulnerabilities in cloud solutions, container technologies, web app frameworks, maritime systems and anything else that can be reused by the larger security community. In the past, he has led multiple security testing teams, include the one at Appsecco which is responsible for the assessment and delivery of Web, Mobile Application and Cloud Security Testing engagements. He is a OSCP and CREST certified Web Application Pentester, security evangelist and researcher. He has been active in the security community for the better part of the last 12 years. He has been actively involved with the Bangalore OWASP and null chapter for the last 9 years and is one of the OWASP Bangalore chapter leads.

In his time in the security industry, Riyaz has penned two books, has trained and spoken at numerous security conferences and helped many Fortune 500 companies become secure by training their teams, testing their apps and responsibly disclosing security weaknesses in enterprise software.

When not dabbling in security research or testing, Riyaz likes to spend his time reading, travelling and stargazing.


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