The two researchers say that they have found ways to seize control of laptop computers by manipulating buggy code in wireless device drivers. In a videotaped demonstration at the conference, Maynor showed how to use sophisticated hacking tools to add and remove files on a Wi-Fi-enabled MacBook, manipulating the system from an adjacent laptop computer.

Wireless devices are designed to be constantly sniffing for new networks, and this can lead to security problems, especially if their driver software is buggy.

This can often happen as vendors rush to implement the complex wireless standards, says Ellch, a student at the US Naval postgraduate school in Monterey, California. "A lot of hardware manufacturers have to ship stuff quickly," he said. "One of the things that gets sacrificed in the speed game is security."

Apple is not the only vendor to have problems with its wireless drivers, says Maynor, who is a researcher with SecureWorks. By exploiting bugs in four different wireless cards, the researchers found ways to seize control of laptops running Windows and Linux as well, they say.

"Do not think that just because we are attacking Apple that the flaw itself is in Apple," Maynor says. "We wanted to do some other demos and they were not panning out."

However, Maynor said that the researchers knew that if they showed their demonstration on a Mac OS X system - generally considered to be a very secure platform - that show attendees would take their findings seriously.

The idea of poking a hole in Apple's current advertising campaign, which smugly boasts that Mac OS X is more secure than Windows, also appears to have been a factor. "I have to be honest, those Mac commercials they just jump right out at you," Maynor told attendees.

The researchers are now working with Apple to fix the problems, which may involve both operating system and driver patches, according to Maynor. Apple declined to comment for this story.

The Black Hat demonstration came just days after Intel issued patches for wireless driver flaws that could lead to the same problems that the researchers demonstrated in Las Vegas.

Maynor and Ellch could not say whether Intel's patches addressed flaws that they had discovered, but they said that they had not worked with the chipmaker on these fixes.

It is possible that the Intel patches were released in anticipation of their talk, the researchers say. Still, both men praised Intel for addressing driver security. "You have to admire a company that would proactively fix things before a talk instead of waiting until afterward," Ellch adds.

Maynor and Ellch's presentation got high marks from last year's most-talked-about Black Hat presenter, Michael Lynn, who was sued by Cisco after disclosing vulnerabilities in Cisco's Internetworking Operating System. "That was pretty awesome," Lynn said, as the two were mobbed by show attendees after their talk.