15 May

Information Disclosure Vulnerability in FV Player (FV Flowplayer Video Player)

Earlier today we noted a security company putting out inaccurate information on vulnerabilities in a WordPress plugin. That isn’t uncommon, as while looking into who might have discovered a recent vulnerability we found NinTechNet suggesting updating the plugin, FV Player (FV Flowplayer Video Player), to version 7.3.13.727:

WordPress “FV Flowplayer Video Player” plugin (40,000+ active installations) fixed XSS vulnerability. Update to v7.3.13.727.

The problem with that is that the vulnerability was fixed in the next release.

We know that because we actually looked in to the vulnerability while adding it to the data set for our service, but before we were even able to understand the vulnerability being fixed we found another related vulnerability, as it turns out that anyone can get a copy of the email subscriptions lists the plugin stores. That is a far too common issue and it why we specifically look for vulnerabilities when doing security reviews of plugins chosen by our customers or when a security review is ordered separately from us.

Before we get to the details of that, it is worth noting that the plugin seems likely to be more broadly insecure and really could use a proper security review, as, for example, it has this line that looks like it is trying to prevent SQL injection using addslashes():

$count = $wpdb->get_var('SELECT COUNT(*) FROM ' . $wpdb->prefix . 'fv_player_emails WHERE email="' . addslashes($data['email']) . '" AND id_list = "'. addslashes($list_id) .'"' );

The documentation for that specifically warns against doing that:

The addslashes() is sometimes incorrectly used to try to prevent SQL Injection. Instead, database-specific escaping functions and/or prepared statements should be used.

CSV Export

In the file /models/email-subscription.php if the GET input “fv-email-export” is not empty and the GET input “page” equals “fvplayer” the function csv_export() runs during admin_init:

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if( !empty($_GET['fv-email-export']) && !empty($_GET['page']) && $_GET['page'] === 'fvplayer'){
  add_action('admin_init', array( $this, 'csv_export' ) );
}

By requesting the right WordPress file that function will run without the requester having to be logged into WordPress.

That function doesn’t do a capabilities check to restrict who can access it and instead just provides a CSV with the contents of an email subscription list specified by the GET input “fv-email-export”:

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  function csv_export(){
    $list_id = $_GET['fv-email-export'];

Due to the moderators of the WordPress Support Forum’s continued inappropriate behavior we are full disclosing vulnerabilities in protest until WordPress gets that situation cleaned up, so we are releasing this post and then leaving a message about that for the developer through the WordPress Support Forum. You can notify the developer of this issue on the forum as well. Hopefully the moderators will finally see the light and clean up their act soon, so these full disclosures will no longer be needed (we hope they end soon). You would think they would have already done that, but considering that they believe that having plugins, which have millions installs, remain in the Plugin Directory despite them knowing they are vulnerable is “appropriate action”, something is very amiss with them (which is even more reason the moderation needs to be cleaned up).

Update: To clear up the confusion where developers claim we hadn’t tried to notify them through the Support Forum (while at the same time moderators are complaining about us doing just that), here is the message we left for this vulnerability:

Proof of Concept

The following proof of concept will provide a CSV of the email subscription list with ID 1.

Make sure to replace “[path to WordPress]” with the location of WordPress.

http://[path to WordPress]/wp-admin/admin-post.php?page=fvplayer&fv-email-export=1

Is It Fixed?

If you are reading this post down the road the best way to find out if this vulnerability or other WordPress plugin vulnerabilities in plugins you use have been fixed is to sign up for our service, since what we uniquely do when it comes to that type of data is to test to see if vulnerabilities have really been fixed. Relying on the developer’s information, can lead you astray, as we often find that they believe they have fixed vulnerabilities, but have failed to do that.


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