It seems that at least some WordPress installations (at least 3.7 and 3.8) allow an infinite number of repeating category slugs instead of giving a 404, ie: site.com/news/2012/news/2012/news/2012/news/2012/news/2012/news/2012/news/2012/
I have a couple of WordPress installations which have this issue, at least one is running W3TC with page caching on, and somehow a crawler or something is calling some URL's with a long repeating permalink... which creates a large complete directory structure with some files.
This creates 2 issues, the first is that emptying the pagecache from the backend times out, and it isn't emptied completely.
The second is created by Wordfence, which scannes the files for vulnerabilities, because the directory structure goes very deep, the scanning takes long and takes a lot of cpu %... which slows down the entire webserver :p
The issue is kind of fixed when I turn off the page caching, but I dont want that because it slows down the website, and creates more mysql queries...
Is there some solution for this?