XSS (Cross-Site Scripting) is a type of website security problem where an attacker injects malicious scripts (usually small pieces of JavaScript code) into a website so that the code runs in other users’ browsers.
In simple words:
XSS is when someone hides harmful code inside a website so it runs on other people’s computers without them knowing.
Imagine This Simple Scenario
Think of a website like a public notice board where anyone can post messages.
Normally, a user posts:
“Hello everyone!”
But a bad actor posts a message that secretly contains hidden instructions.
When other visitors read that message, their browsers unknowingly follow those hidden instructions.
That hidden instruction is similar to XSS code.
Very Simple Example
Normal comment on a website:
Nice article!
XSS attempt:
Nice article! <hidden script here>
If the website does not filter what users post, the hidden script can run in the browser of anyone who views the page.
What Can XSS Do?
On an insecure website, XSS can allow someone to:
- Steal login session cookies
- Redirect users to fake pages
- Display fake messages or pop-ups
- Change website content temporarily
- Collect user information from forms
It mainly affects visitors, not just the website owner.
Why XSS Happens
XSS usually happens when:
- A website does not sanitize user input
- Comment boxes or forms accept raw code
- Developers forget to escape special characters
- No security filtering is applied to user content
Easy Analogy
Imagine a school notice board where students are allowed to pin notes.
A normal note says:
“Football practice at 4 PM.”
A harmful note secretly says:
“Football practice at 4 PM — also give me your ID card.”
If people follow the hidden instruction without realizing it, that’s similar to how XSS works online.
Key Idea to Remember
XSS = Injecting hidden scripts into a website so they run in other users’ browsers.
It happens because the website trusts user input too much.
🚀 Learn Cybersecurity
