Cybercriminals are wasting no time in taking advantage of a Joomla security flaw that allows them to perform SQL injection attacks and take over websites.

The Joomla security bug involves extracting cookies during a user’s session and then using it to log in as an administrator. The developers of the content management system (CMS) have already released a new version to fix the problem, but it’s probably safe to say many of the 2.8 million sites that use Joomla have yet to make the necessary changes.

In fact, researchers at Sucuri published a blog post confirming that SQL injection attacks started coming within about four hours of the news about a Joomla security risk. To be fair, the researchers noted that the attacks took place when it was night in Europe, when webmasters were probably not awake and had yet to learn about Joomla 3.4.5. Some of the attacks Sucuri spotted were not actual exploits but a sort of test to determine if a particular site would be vulnerable. In other words, cybercriminals are not acting impulsively but instead are methodically planning their next move.

Softpedia noted that after the first few attempts, the Joomla security attacks scaled up rapidly to reach a high of 12,000 per day. Cybercriminals clearly know what they’re doing, too, checking for specific versions of the CMS on a site in order to hit a more vulnerable target. Given that the flaw affects Joomla 3.2 through 3.4, there’s a fairly wide potential list of sites that need to make sure they’re safe from harm.

Of course, as more organizations move to the most recent version of the CMS, Joomla security attacks could diminish as quickly as they escalated. According to PCWorld, however, CISOs and their teams need to recognize that they really only have a day to fend off the worst of the threats, and probably a lot less than that if their domain attracts a considerable amount of traffic. Cybercriminals are proving highly proactive and responsive to any security hole that opens up to them. Enterprises need to be just as quick to act if they don’t want to lose control over their websites and data.