IDG News Service —

Adobe Systems has released a new version of its Flash Player software, fixing a critical security bug that could make the Internet a dangerous place for Web surfers.

The new Flash Player 10 software, released Wednesday, fixes security flaws in Adobe's multimedia software including bugs that could allow hackers to pull off what's known as a clickjacking attack, wrote Adobe spokesman David Lenoe in a blog posting.

For those who can't update to this new version of Flash, a Flash 9 security patch is still about a month off, he added. Adobe rates the clickjacking bug as 'critical.'

Although not widely used by criminals, clickjacking has received a lot of attention since it was first discussed a month ago. Flash isn't the only software that is vulnerable to a clickjacking attack, but Flash attacks have been considered among the most dangerous.

The security researchers who discovered the problem, Robert Hansen and Jeremiah Grossman, had intended to fully discuss clickjacking at a Sept. 24 security conference presentation. But they backed off and gave a slimmed-down version of their talk when Adobe asked for more time to patch its software.

Last week, however, security researcher Guy Aharonovsky showed how an Adobe Flash clickjacking attack would work, and with the information now out in the open, Hansen and Grossman went public with their findings.

In a clickjacking attack, the hacker users a variety of techniques to take control of what links the victim is actually clicking. In one attack, for example, the attacker would first have to trick the victim into visiting a malicious Web page and then clicking on what appeared to be a regular Web link. In reality the victim would be clicking on something altogether different such as a Flash object that turned on his microphone. "It's almost impossible for a user to determine what's going to happen when they click on a link," said Hansen, who is CEO of SecTheory.com, in an interview last week.

A clickjacker could wiretap victims' PCs, force them to execute online stock trades, delete blog pages, change a router or firewall configuration, create new Web mail accounts, or even force them to download software, Hansen said.

Because clickjacking affects other browser plugins, the best way to fix the clickjacking problem may be to change the way browsers work, Hansen said. "Browser makers understand the problem and they're trying to find ways to mitigate it," he said.