A security researcher has called foul on Microsoft for doing exactly what it has thrashed hackers over for years: revealing information that can be used to hijack computers before a patch is available.

Swa Frantzen, one of the analysts at SANS Institute's Internet Storm Center (ISC) criticized Microsoft for issuing patches Tuesday that fix the Windows versions of PowerPoint while announcing that patches for the same flaws in the Mac editions would not be released until June.

“Microsoft is the one big company screaming loudest over ‘responsible disclosure,’” said Frantzen in a post to the ISC blog late Tuesday. Responsible disclosure, a practice Microsoft has aggressively pushed, demands that researchers delay any disclosure until the bug has been patched. “They want an unlimited amount of time to release their patches before those who found the problem are allowed to publish,” said Frantzen. “[But the] policy cuts both ways: You need to obey the rules yourself just as well as demand it from all others involved.”

Microsoft, claimed Frantzen, broke its own rules of responsible disclosure Tuesday by revealing that Office for Mac 2004 and Office for Mac 2008 contain three unpatched vulnerabilities, and by releasing information about the same bugs in Windows. The combination, he said, could be used by hackers to craft exploits targeting Macs.

“We all know from past experience [that] the reverse engineering of patches back into exploits starts at the time—if not before—the patches are released,” said Frantzen. “So in the end, Microsoft just released what hackers need to attack.”

An online poll that Frantzen posted on the ISC site showed that 47 percent agreed Microsoft had been irresponsible in omitting patches for the Mac, while about 24 percent thought Microsoft made the best-possible decision.

John Pescatore, an analyst for Gartner who covers security, agreed with the minority. “I think Microsoft did the right thing here,” he said in an e-mail. “I would much rather see solid, well-tested patches for the highest risk vulnerabilities—which means first the ones where there are active exploits out—come out first, rather than wait for all versions to be patched simultaneously, or to rush out immature patches quickly and require re-patching later.”

Andrew Storms, director of security operations at nCircle Network Security, took a middle path. “I wouldn’t say that [Frantzen] has gone too far. Microsoft really owns ‘responsible disclosure,’ both in the PR sense and in the sense that they’ve been able to get researchers to do it,” said Storms. “You don’t break your own mantra.

“Regardless, I disagree with him,” Storms continued, “simply because the proof-of-concept code has been out there for a month.” If no one has taken that sample code, and used it to investigate, then create a working exploit for the Mac in the past month and more, Storms argued, it was very unlikely that they would go to the additional work of reverse engineering the Windows patches to figure out how to build an exploit for the Mac.

“Why would they take the harder path,” Storms asked, “when they haven't taken the easier?”

Microsoft was not able to immediately provide someone from its security response center to argue the company’s side of the responsible disclosure debate, but Tuesday it explained the decision to release PowerPoint patches for Windows but not for Mac OS X.

“None of the [PowerPoint] exploit samples we have analyzed will reliably exploit the Mac version, so we didn’t want to hold the Windows security update while we wait for Mac packages,” said Jonathan Ness, an engineer with the Microsoft Security Response Center, in a post to a company blog.

This story, "Researcher: Microsoft puts Mac users at risk with patch policy" was originally published by Computerworld .