The Security Risks That Could Be Lurking in Your WordPress Backup Plugin

One of the things that we have noticed in looking at security vulnerabilities in WordPress plugins over the years is that backup plugins are often found to have vulnerabilities. While working on our new plugin that lets you know what vulnerabilities are or have in the past existed in the WordPress plugins you use we have seen that the poor security of backup plugins is continuing. Two examples highlight the problems with security of not just backup plugins, but all plugins.

DB Backup Plugin

Because backup plugins create files containing sensitive data, backup plugins need to prevent unauthorized users from downloading those files. One way to do that is block direct access to the files and then permit users to download them through the plugin. Unfortunately that can introduce a new security risk since if the download mechanism is not secured it can be abused to download files that someone shouldn’t have access to. That is the case with the plugin DB Backup, which was found to allow anyone to download arbitrary files from the website. That could for example be used to download the wp-config.php and therefore provide the login credentials for the website’s database.

The bigger problem that this highlights is what happens when a security vulnerability doesn’t get fixed, as is the case with this plugin. Right now if you go to the page for this plugin https://wordpress.org/plugins/db-backup/ you get served a search page:

This is due to the plugin being pulled from the Plugin Directory, probably due to someone notifying WordPress of the issue. This prevents anyone from downloading the plugin, but what about people that already have it installed? Unfortunately they are not given any notice that they are using a plugin with a security vulnerability. That obviously shouldn’t be the case, but despite our pushing for that to change for years WordPress still has corrected this issue. If you would like to see that change then please vote for that to happen.

XCloner – Backup and Restore

Another general problem with plugins is that the developers don’t always have much concern for security. The developer of the XCloner – Backup and Restore plugin falls in to that category, which has put the users of the plugin at risk in multiple ways.

The most recent vulnerability discovered in the plugin allowed any one who could log in to WordPress to download any backup files created by XCloner. What is of more concern is the developer’s response. The person who discovered vulnerability states that they notified the developer on November 7 and 13, the vulnerability wasn’t fixed after either of those. It also wasn’t fixed after the vulnerability was publicly disclosed on November 19. It finally got fixed within a day of us reporting the vulnerability to WordPress and the plugin being pulled pending a fix. You can see they only had to make minor changes to fix the issue, so this could have easily been fixed before if they had been interested. If we hadn’t reported the vulnerability it is quite possible the vulnerability still wouldn’t have been fixed.

This isn’t an isolated incident. Below is the list of the unsuccessful attempts a security company made to notify of them of vulnerabilities in a standalone version of XCloner:

- 6 notifications by email
– 4 notifications via contact form
– 1 notification via twitter.

The latest vulnerability is one of five that have been discovered in the plugin. The others are:

The developer’s lack of concern for security isn’t just for their software, seeing as their website is currently running a nearly four year old version of WordPress: