Merry Christmas, now go patch your Wordpress installation

Exploit: http://git.zx2c4.com/w3-total-fail/tree/w3-total-fail.sh

Screencast: http://git.zx2c4.com/w3-total-fail/plain/screencast.ogv or https://www.youtube.com/watch?v=sqZ_zYLFDSo

Note that this isn't a bug in WordPress itself, but in the W3 Total Cache plugin.

So, could someone un-editorialize the title, please?