As plugins’ usage of the WordPress’ REST API increases security issues related to that are increasing. The recently introduced plugin WebP Converter for Media is another example of that. One of the changelog entries for a recent version of that is “Securing access to REST API”. Looking at the changes made in that we found that there were checks added to restrict access to the plugin’s REST API functionality and that previously anyone could access them. It looks like those would allow getting a list of image files in the WordPress media library and converting images files stored with that to the WebP format.

...

---

This post provides insights on a vulnerability in the WordPress plugin WebP Converter for Media not discovered by us, where the discoverer hadn't provided the details needed for us to confirm the vulnerability while we were adding it to the data set for our service, so the rest of its contents are limited to subscribers of our service.

If you were using our service, you would have already been warned about this vulnerability if your website is vulnerable due to it. You can try out our service for free and then see the rest of the details of the vulnerability.

For existing customers, please log in to your account to view the rest of the contents of the post.