03 Nov

Not Really a WordPress Plugin Vulnerability – Week of November 3, 2017

In reviewing reports of vulnerabilities in WordPress plugins we often find that there are reports for things that don’t appear to be vulnerabilities. For more problematic reports we have been releasing posts detailing why the vulnerability reports are false, but there have been a lot of that we haven’t felt rose to that level. In particular are items that are not outright false, just the issue is probably more accurately described as a bug. We have been thinking that providing information on why those are not included in our service’s data could be useful, so we are trying out putting a weekly post when that occurs detailing those issues.

Full Path Disclosure in Inline Image Upload for BBPress

At the end of September we mentioned that the website WPCampus wasn’t properly crediting us when discussing things we had written, but it isn’t just us that is true with us. Last week in their post on plugin vulnerabilities they credited Wordfence for discovering a vulnerability, but for the other claimed issue they discussed they left out any mention of the discoverer:

For this week’s unfixed vulnerabilities, the Full Path Disclosure issue with the Inline Image Upload for BBPress (and it’s Pro version) isn’t a vulnerability by itself, but can be used in combination with other attacks that require knowing the server path. Hopefully the vendor will release a fix soon, but if not, you can mitigate this issue by ensuring display_errors is disabled for php for your site.  The specifics of how you disable it will depend on your hosting set up.  If you’re not sure, contact your hosting provider or system administrator.

In looking at the linked spreadsheet with the details, we immediately noticed it looked like this wasn’t really a vulnerability as it said in the note for it, “Ensure error_reporting/display_errors is turned off/disabled”. As we noted back in May with a claim made by Wordfence if you consider this a vulnerability then WordPress is also vulnerable:

So is that a vulnerability? We would say probably not if it doesn’t display when error reporting isn’t enabled (though the issue in this plugin could easily be fixed), but if it is, there is a much larger issue because the same thing will occur in the core WordPress software. For example, if you were to visit /wp-includes/wp-diff.php with error reporting enabled you would get this:

Warning: require(ABSPATHWPINC/Text/Diff.php): failed to open stream: No such file or directory in [redacted]/public_html/pluginvulnerabilities.com/wp-includes/wp-diff.php on line 13

Fatal error: require(): Failed opening required ‘ABSPATHWPINC/Text/Diff.php’ (include_path=’.:/usr/local/lib/php’) in [redacted]/public_html/pluginvulnerabilities.com/wp-includes/wp-diff.php on line 13

WPCampus isn’t the only source of WordPress plugin vulnerabilities passing along inaccurate information on vulnerabilities that we ran across this week. During our monitoring of the WordPress Support Forum we looked at thread bringing up a claimed vulnerability in the plugin Comment Attachment. The message from the plugin Vulnerable Plugin Checker that uses data from the WPScan Vulnerability Database shown in the thread stated:

Comment Attachment has a known vulnerability that may be affecting this version. Please update this plugin.

Comment Attachment 1.0 – XSS

That isn’t all that helpful to someone trying to figure out what is going on. Looking at the relevant entry in WPScan’s data pointed to the source of the claim. The instructions for exploiting the claimed issue are as follows:

1) Download “Comment Attachment” And Install
2) Go To Sitting Comment Attachment :
Settings > Discussion > Comment Attachment
3) Insert In “Attachment field title” This Code And Save :
“><script>alert(/Arsan/)</script>
4) And Try To See Your Post And Comment; Follow Link :
http://localhost/wp/?p=1

To access that page you have to have the “manage_options” capability. Users with the “manage_options” capability would normally only be Administrators (and if others are given the capability they would normally be able to create Administrators accounts), which would normally have the “unfiltered_html” capability and therefore could do the equivalent of this.

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