cross site scripting xss explained how to bug bounty

Download 1M+ code from https://codegive.com/2380f88
cross-site scripting (xss) explained

what is xss?

cross-site scripting (xss) is a security vulnerability that allows an attacker to inject malicious scripts into web pages viewed by other users. these scripts can execute in the context of the user's browser, leading to various attacks such as session hijacking, data theft, or redirecting users to malicious sites.

types of xss

1. **stored xss**: the malicious script is stored on the server (e.g., in a database) and is served to users when they request the affected page.

2. **reflected xss**: the malicious script is reflected off a web server, usually via a url. this type requires the victim to click a link crafted by the attacker.

3. **dom-based xss**: the vulnerability exists in the client-side code rather than the server-side. the script is executed as a result of modifying the dom.

how does xss work?

1. an attacker finds a way to inject javascript code into a web page.
2. the malicious script runs in the context of the user's browser.
3. the script can perform actions like stealing cookies, capturing keystrokes, or manipulating the dom.

example of a simple xss attack

let's say we have a web application that takes user input and displays it back without proper sanitization:

```html
!doctype html
html lang="en"
head
meta charset="utf-8"
titlewelcome page/title
/head
body
h1welcome to our site!/h1
form method="get" action=""
label for="name"enter your name:/label
input type="text" id="name" name="name"/
input type="submit" value="submit"/
/form
div id="greeting"
script
// this displays the user's input directly in the html
document.write("hello, " + new urlsearchparams(window.location.search).get("name"));
/script
/div
/body
/html
```

if a user enters `"scriptalert('xss attack!')/script` in the input field, the resulting html would be:

```html
div id="greet ...

#CrossSiteScripting #XSSExplained #gk
Cross Site Scripting
XSS Explained
Bug Bounty
Web Security
Vulnerability Assessment
Penetration Testing
JavaScript Injection
Security Testing
XSS Prevention
Ethical Hacking
Application Security
Threat Modeling
Security Awareness
Cybersecurity
Exploit Development