Adobe Systems this week plugged the Flash Player hole used by a hacker two weeks ago to take down a Windows Vista machine and claim a US$5,000 prize in the "PWN To OWN" exploit challenge.

Adobe's update to Flash Player -- the popular program and browser plug-in used to view online content -- patched seven vulnerabilities, including several that could be used by attackers to hijack machines running the flawed software. Among the seven was the one used to break into a Fujitsu notebook during the hacker contest sponsored by 3Com's TippingPoint, which operates a bug bounty program called Zero Day Initiative.

Last week, Adobe claimed it had known about the Flash bug before it was used by Shane Macaulay of Security Objectives to hack one of the laptops up for grabs at CanSecWest, and would add a fix for it to a previously scheduled update this month.

Adobe had announced the April update about four weeks ago, but had left the timeline vague, saying only that it would refresh Flash sometime during the month.

The majority of the patches applied to Flash Player quashed bugs in how the software handled .swf files, the proprietary Shockwave Flash format. One of the .swf vulnerabilities had been reported to Adobe back in December 2007 by Google researcher Rich Cannings, who pointed out the format could be used to launch cross-site scripting attacks, which are commonly deployed by identity thieves and phishers.

Earlier, Adobe had issued updates to its Web developer tools that crank out .swf files, and told Web operators and site designers to make changes to their pages before it released yesterday's end-user update. If they didn't get rid of the older .swf files, they risked users being unable to access Flash content on their sites, Adobe warned.

It repeated the warning yesterday. "Due to the possibility that these security enhancements and changes may impact existing Flash content, customers are advised to review this March 2008 Adobe Developer Center article to determine if the changes will affect their content," said Adobe in the advisory yesterday that accompanied the Flash Player update.

Simultaneously, TippingPoint -- via its Zero Day Initiative (ZDI) bug-buying program -- released a few details about the vulnerability it acquired from Macaulay during the PWN To OWN contest. "Exploitation of this vulnerability can result in arbitrary code execution under the context of the currently logged in user," said ZDI's own advisory. Adobe said all versions of Flash Player, which comes in editions for Windows, Mac OS X and Linux, were affected by the vulnerabilities and should be updated.

Users can update by manually downloading the new edition of Flash Player from the Adobe site, or using the auto-update feature embedded in the software.