Virally growing attacks on unpatched WordPress sites affects ~2m pages
arstechnica.com
arstechnica.com
So far, the vulnerable sites under these new attacks are those
running WordPress plugins such as Insert PHP and Exec-PHP, which
allow visitors to customize posts by inserting PHP-based code
directly into them.
This is never a good idea. Don't allow your content admins to add executable code to a CMS!