Most websites you visit - including mine - are running some kind of content management system. A CMS makes it easy to update content on a website without having to edit the site's code directly.
Trust me; when you're posting more than a dozen new pages every day, it's a lifesaver.
There are hundreds of CMS options, but one of the most popular is the free Drupal. It's estimated to be on nearly 6% of all websites, or around 12 million.
That means if it runs into problems, a lot of websites are going to be in trouble, and that's just what happened earlier this month.
Drupal discovered a serious flaw in the Drupal 7 code that could let hackers modify or even take over a site. It rushed out a patch on October 15 to fix the problem, but within seven hours hackers were already launching automated attacks against Drupal-based websites.
Drupal is now telling site owners that if they failed to upgrade within seven hours of the patch appearing, they should assume their site is compromised. Not many websites update their systems that quickly, so millions of sites are at risk.