The Code Red and Nimda worms revealed severe problems in Microsoft's security alerting system. Despite the availability of patches weeks before either worm hit the Internet, few users--particularly enterprises--deployed them.
The problem was twofold: Some users found Microsoft's advisories difficult to understand or didn't receive them at all; others had a difficult time obtaining and verifying the patch. The situation prompted a complete revamping of the Microsoft Security Response Center (MSRC), the gateway for vulnerability reports and security fixes.We always took security seriously and were committed to it, but much more of the company takes it much more seriously in the aftermath of Code Red and Nimda.
directorMicrosoft security assurance
"We always took security seriously and were committed to it, but much more of the company takes it much more seriously in the aftermath of Code Red and Nimda," says Steve Lipner, director of security assurance, who oversees the MSRC. "We know it's important to get it all right and get it out to our customers, and everyone knows what can happen if we don't get it out."
All vulnerability reports filed with MSRC are put through a sophisticated triage and tracking process. The vulnerability report is sent to the appropriate development team, which is responsible for replicating the problem and developing a fix for it. At the same time, an independent engineering team does an evaluation to verify the problem and potential remedies.
Once a patch is created, it goes through a vetting process to ensure it works as intended.
"Our long-term vision is that we will achieve a level of quality in the security patches that we build so people will be comfortable with installing them," says Scott Culp, the former MSRC manager who recently transferred to Microsoft's Security Strategies Group. "Eventually, [we want to] reach a level of quality so people will feel comfortable with automatically installing [them]."
To facilitate patch distribution and deployment, Microsoft developed a patch management service, which works much the same as Windows Update. It automatically downloads patches to a local server, where enterprises can evaluate and test them before pushing them to endpoints.
MSRC is also correlating security vulnerabilities, releasing more cumulative patches that correct multiple vulnerabilities at once. "If we have multiple issues that affect a single component, we'll try to package them together to minimize the impact on administrators," says Lipner.
One area Microsoft says needs work is the vulnerability rating system. MSRC instituted severity ratings early last year to help admins determine the criticality of vulnerabilities and patches. The system has been plagued by mistakes, forcing MSRC on occasion to print retractions or upgrade vulnerability ratings. MSRC has revised the process at least twice, but is still struggling to make it work.
"They continue to appear to miss the boat when it comes to assessing the severity because they continue to supply mitigations that don't seem to apply, or at least, misrepresent their effect on the severity of a given issue," says Russ Cooper, editor of NTBugtraq and surgeon general at security assurance firm TruSecure (TruSecure publishes Information Security).
Culp admits the process is subjective, but does provide valuable information for end users. "It's very difficult to come up with a single rating that's meaningful and applicable to everyone that allows people to understand where to take a delta for their own situation," he says. "It's going to be an inexact science, and for some people it won't be critical because of the way they've deployed a product."