Microsoft Guru Wants Vista Bugs Rated Less Serious

Microsoft's own bug hunters should cut Windows Vista some slack and rate its vulnerabilities differently because of the operating system's new, baked-in defenses, according to the developer who is often the public persona of the company's Security Development Lifecycle (SDL) process.

Michael Howard, a senior security program manager in Microsoft's security engineering group, said that the Microsoft Security Response Center (MSRC) is being too conservative in its Vista vulnerability rating plans. Because Vista includes security techniques and technologies that Windows XP lacks, the MSRC should reconsider how it ranks Vista when a vulnerability affects both Microsoft's new operating system and its predecessor, Windows XP, he said.

"The MSRC folks are, understandably, very conservative and would rather err on the side of people deploying updates rather than trying to downgrade bug severity," said Howard on his personal blog last week. "Don't be surprised if you see a bug that's, say, Important on Windows XP and Important on Windows Vista, even if Windows Vista has a few more defenses and mitigations in place."

The operating system, released to consumers in late January, includes a number of new security features that randomize memory, check code for buffer overflows and require user permission for potentially risky operations.

Not surprisingly, the MSRC rejects Howard's argument. "Windows Vista will not be treated any differently, and severity ratings for any issues will be based on vulnerability traits and merits, along with technical mitigating factors," an MSRC spokesperson said. "This process is the same for all Microsoft products."

Although the MSRC's security bulletins may qualify a bug's severity in some specific environments, its rating system is clear-cut. If an Internet worm can spread without user action -- the MSRC's definition of "critical" -- on Vista, the vulnerability will be so tagged, Vista-specific security technologies notwithstanding.

Analysts and outside Microsoft security professionals took the MSRC's side -- and blasted Howard's idea.

"A remote-code execution exploit still remains a remote-code execution exploit," said Johannes Ullrich, chief research officer at the SANS Institute.

"[Windows] either has the vulnerability or it doesn't," said Marc Maiffret, eEye Digital Security's CTO. "Vista has some additional Band-Aids, but most of those Band-Aids are broken. Hopefully, [Microsoft] isn't so careless that they'll downgrade Vista vulnerabilities."

Other researchers and analysts gave Vista more credit for its beefed-up security than did Maiffret, but most noted that just because Vista has new security features doesn't necessarily mean they'll be used. "They may or may not be turned on," said John Pescatore, an analyst at Gartner Inc. "And users can be tricked, and attackers can get around defenses. I definitely don't think Microsoft should change things."

Oliver Friedrichs, senior director of Symantec Corp.'s security response team, agreed. "If past history is any indication, exploitation is more like an art and less like a science," Friedrichs said. "Attackers have found ways around defenses in the past to exploit vulnerabilities. [User Account Control], for example, doesn't present as much of a hurdle to attackers as once thought. Even Microsoft is saying that."

Microsoft has also been saying that Vista will prove to be more secure than any earlier version of Windows, an opinion Howard shares. "Here's my prediction: We will see significantly less critical vulnerabilities in the operating system over the next two years, as compared to Windows XP, perhaps by a factor of as much as 50 percent, and a 30 percent reduction of important vulnerabilities."

Howard's forecast is in line with other recent estimates by Microsoft executives, including Ben Fathi, the former head of Microsoft's security group and now the chief of development in the Windows core operating system group. Last month, Fathi set a goal of half as many Vista vulnerabilities in its first year as XP had in its first 12 months.

"Why am I making these claims?" said Howard. "I know that SDL works, and we will continue to evolve SDL over time as we learn of new vulnerability types and new defenses."

Ullrich is counting on Vista's vulnerabilities to be few and far between, too -- but for a very different reason. "The limited pickup of Vista installs [means that] until Vista is more popular, it will enjoy the same limited attention from hackers as OS X."

This story, "Microsoft Guru Wants Vista Bugs Rated Less Serious" was originally published by Computerworld.

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