Date: Sun, 22 Aug 2010 17:25:27 +0100
From: Darren McDonald <athena@...donald.net>
To: full-disclosure@...ts.grok.org.uk
Subject: VWar 1.6.1 R2 Multiple Remote Vulnerabilities

Back in April 2008 I found a bunch of vulnerabilities in PHP clan management
system, however the project had just changed hands. Since then the new
project leader has been assuring me that new secure release which fixed all
the found issues was just around the corner. Over two years later I remember
I'm still hanging on to these issues, so I think it is time to release them,
patch or not. The SQL injection issue was released on
http://www.securityfocus.com/bid/29001 back in May 2008, as project reverted
to an older version which was not vulnerable to this issue. Here is the
orginial list of findings.

Best,

Renski

A copy of this document can be found at dmcdonald.net/vwar.txt

1. SQL Injection

    1.1 Summary

    An SQL Injection vulnerability has been discovered in the article rating
system in
    http://mydomain.com/vwar/article.php This issue could be used by an
attacker to
    deface articles, deny service to other users (DoS), and other SQL
Injection
    related issues.

    1.2 Technical Details

    The bug itself is in vwar/article.php, line 44

    39  if (is_numeric($GPC["rate"])){
    40          if ($GPC["ratearticleselect"] && $GPC["ratearticleselect"]
<= 6){
    41
    42                  $vwardb->query("UPDATE vwar".$n."_article
    43                  SET
    44                   articleratingpoints  =
articleratingpoints+".$GPC["ratearticleselect"].",
    45                   articlerated = articlerated+1
    46                  WHERE articleid = '".$GPC["rate"]."'");
    47
    48                  $redirecturl =
"article.php?articleid=".$GPC["rate"];
    49                  include ($vwar_root . "includes/get_header.php");
    50
eval("\$vwartpl->output(\"".$vwartpl->get("message_confirmation")."\");");
    51                  include ($vwar_root . "includes/get_footer.php");
    52                  exit();
    53           } else {
    54           ...

    A proof of concept can be seen in the following post request which
results in
    the main body of the article being replaced with the text 'NGS TEST'

    POST /vwar/article.php?rate=1 HTTP/1.1
    Host: mydomain.com
    User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.8.1.13)
Gecko/20080311 Firefox/2.0.0.13
    Accept:
text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
    Accept-Language: en-gb,en;q=0.5
    Accept-Encoding: gzip,deflate
    Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
    Keep-Alive: 300
    Proxy-Connection: keep-alive
    Referer: http://mydomain.com/vwar/article.php?articleid=1
    Content-Type: application/x-www-form-urlencoded
    Content-Length: 64

    ratearticleselect=5, article = char(78,71,83,32,84,69,83,84)

    It is also possible to cause vwar to run out of memory when attempting
to
    display the article by setting ratearticleselect to a high enough value,
for example;

    ratearticleselect=5%2b999999

    when the article in question is requested by a user, vwar will run out
of memory
    attempting to generate html containing vast numbers of IMG tags to
display the
    star rating.

    1.3 Workaround

    There is no known workaround for this issue.

2. Stored Cross Site Scripting (XSS)

    2.1 Summary

    Five entry points for stored XSS have been found in the following
locations

    http://mydomain.com/vwar/challenge.php
    http://mydomain.com/vwar/joinus.php
    http://mydomain.com/vwar/admin/admin.php?action=finishwar&warid=1
    http://mydomain.com/vwar/profile.php

    However, there are likely to be more as vwar uses a common set of text
parsers
    to protect again XSS and SQL code injection.

    This issue can be used to attack other users of the vwar system,
including the
    administrators, as data inputed on these forms is often sent for
administrator approval.
    The results can include session highjacking, which would allow an
attacker to take
    gain admin access.

    2.2 Technical Details

    Issue 1: http://mydomain.com/vwar/challenge.php - Additional Information
input field
    Issue 2: http://mydomain.com/vwar/joinus.php - Additional Information
input field
    Issue 3:
http://mydomain.com/vwar/admin/admin.php?action=finishwar&warid=1 - War
Report input field
    Issue 4: http://mydomain.com/vwar/profile.php - Nick input field
    Issue 5: http://mydomain.com/vwar/joinus.php - Contact information input
field

    The Vwar system filters out <script> tag to prevent XSS, but allows
image (IMG) tags,
    where javascript can be executed on the 'onload', 'onerror', and similar
events. If so, as
    these forms are often sent to users there is the potential for an
attacker to high-jack the
    session of another user, including a user with administrator access.

    A proof of concept which work with all five issue can be seen by
entering the follow html in
    the vulnerable fields

    <IMG src='' onerror=alert(document.cookie)>

    2.3 Workaround
    Risk from issues 1, 2, 3, and 5 can be mitigated by setting turning the
following
    settings to 'Off' in the adminstrators settings page.

    HTML Code (Default On)
    Enable Challenge Requests (Default On)
    Enable Join Requests (Default On)

    There is no known workaround for issue 4.

3. Broken Access Controls

    3.1 Summary

    There is lack of access controls in http://mydomain.com/vwar/popup.phpin the
    print view system which allows an attacker to view articles normally
restricted
    to users of the system.

    3.2 Technical Details

    It is possible to access member only news posts by using the printnews
action
    though the newsid field in popup.php. For example, assuming article 3 is
hidden
    from public view this following url will allow access to a user who has
not
    logged in.

        http://mydomain.com/vwar/popup.php?action=printnews&newsid=3

    where as http://mydomain.com/vwar/news.php?newsid=3 and
    http://mydomain.com/vwar/news.php correctly do not return the news
article
    unless requested by a valid user.

    3.3 Workaround

    There is no known workaround for this issue.

4. Weak Password Generation

    4.1 Summary

    VWar has a fault with it's random password generation function which is
used
    during account creation and the forgotten password functionality.
Passwords
    generated this way are highly likely be one of a set of 60 passwords.

    Vwar has no account lock out system in place to stop an attacker
attempting
    to brute force a password of a valid user, meaning that an attacker with
an
    automated tool can gain access to an account with a randomly generated
    password in only a few seconds.

    4.2 Technical Details

    The bug is in vwar/includes/functions_common.php on line 724

    716  function createRandomPassword ($passlen=15,$chars="")
    717  {
    718      $chars = trim($chars);
    719          if(empty($chars)) $chars =
"aAb0Bc\$CdD1eEfF2gGh%3HiIj§J4kKl5Lm6MnNo7&OpPqQrR6sStTuUvV9wWxXyYzZ§$%&";
    720
    721          $charlen = strlen($chars);
    722          for ($i = 0; $i < $passlen; $i++)
    723          {
    724                  mt_srand(date("s", time() + $i * 4567));
    725                  $password .= substr($chars,mt_rand(1,$charlen),1);
    726          }
    727
    728          return $password;
    729  }

    The mt_srand function is seeded with the number of seconds of the
current
    system time, a limited set of 60 ('00' to '59'). As the seed
predetermines the
    password which will be generated by this function, it is high likely
that the
    password will be one of a set of only 60.

    It is possible (although unlikely) that createRandomPassword could run
    during the transition of one second to the next, meaning there is a
total of 420
    possible password which could be generated.

    With the designed user enumeration in
http://mydomain.com/vwar/admin/index.php?login=1
    and other locations combined with the forgotten password functionality
makes it trival
    to gain access to any account

    4.3 Workaround

    Users with default or reset passwords should be encouraged to reset them
    manually to new secure passwords. However

5. Static Session Cookies

    5.1 Summary

    VWar's session cookies are static, meaning that a user will always be
given the
    same sesion cookie. VWar will also allow authentication based solely on
this
    cookie.  If an attacker obtainers a users session cookie (trival using
finding 2),
    session time outs and the logout function will not disrupt an attacker's
activities.

    5.2 Technical Details

    The session cookie is created by running the php function md5 on the
users
    md5 hashed password, causing the session id to be static.

    5.3 Workaround

    There is no known workaround for this issue.

Content of type "text/html" skipped

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