A bit of holiday fun for Google security researcher Travis Ormandy left Ubisoft scrambling to fix a gaping flaw in its Uplay gaming application on Monday morning.

"While on vacation recently I bought a video game called 'Assassin's Creed Revelations,' he posted on the Full Disclosure mailing list. "I noticed the installation procedure creates a browser plugin for its accompanying Uplay launcher, which grants unexpectedly (at least to me) wide access to websites."

A demonstration page showed how a visitor's browser with the Uplay plugin installed could be made to launch a calculator application as a test case. The problem was initially reported as being a form of rootkit used for monitoring the Ubisoft's DRM system, but the company denied this in a statement to El Reg.

"The issue is not a rootkit. The Uplay application has never included a rootkit. The issue was from a browser plug-in that Uplay PC utilizes which suffered from a coding error that allowed systems usually used by Ubisoft PC game developers to make their games," it said.

The company said that it got the news of the flaw early on Monday morning and had a patch out within 90 minutes, giving a few people a very sudden start to the working week. Around 20 of its most recent games are thought to be vulnerable and Ubisoft advised users to download the patch, shut down all browsers, and run the update to fix the issue.

The rootkit row, although misguided, demonstrates the continuing frustration with some over Ubisoft's latest DRM system, which require some games to maintain a constant internet connection to function. While this is an effective form of DRM, it's cold comfort if your connection goes down seconds before you level up. ®