Microsoft has scheduled just two security updates for Tuesday to fix flaws in Windows 2000, XP and Server 2003. One of the two is a leftover from October that was bumped at the last minute.
Only one of the bulletins will be rated "critical," Microsoft's highest ranking, while the other will be labeled "important," the next-lower rating. As usual, Microsoft disclosed a limited amount of information about the upcoming updates in a prepatch notification posted to the company's Web site today.
The critical update affects Windows XP and Windows Server 2003, said Microsoft, which classified the vulnerability as a remote code execution bug. What the bulletin will fix, however, is up for speculation.
"It could be the Macrovision vulnerability," said Andrew Storms, director of security operations at nCircle, referring to the digital rights management software bundled with Windows that has already been targeted by in-the-wild attacks. "Macrovision has already got a fix, so Microsoft wouldn't have had to do any coding."
Storms noted, however, that Microsoft would have to stretch its usual definition of "remote code execution" to make the Macrovision vulnerability fit the update, since both companies have been calling it a privilege elevation flaw, and thus less serious. "Microsoft sometimes seems to go back and forth about privilege elevation," Storms said. "They might just say, 'sure it's an elevation, but it could also lead to remote code execution.' Or we may just see a reversal here of the bug's severity."
On the other hand, the critical bulletin may be aiming at something completely different. "It could be the URI protocol handler bug," Storms said.
Less than two weeks ago, Microsoft accepted responsibility for fixing a widespread flaw in how Windows deals with the Uniform Resource Identifier (URI) protocol handlers, which let browsers run other programs via commands in a URL. At the time, Bill Sisk, a member of Microsoft's security response team, said that the group was "working around the clock" on a patch. The company would not commit to a release date, however, or say whether it would make the next update rollout, now just a day away.
The debate over who was responsible for patching the problem with the URI protocol handler raged over the summer, when Microsoft denied that its software was at fault, and third-party application vendors, including Mozilla and Adobe Systems, pointed fingers at the company even as they patched their own products.
Tuesday's second update, which targets Windows 2000 and Windows Server 2003 but not XP, appears to be the one that was yanked before October's bulletins hit the Internet. The only hint Microsoft gave of its composition was the "Spoofing" label, which in the past has usually been used to describe vulnerabilities in Internet Explorer that phishers and identity thieves exploit to deceive users.
"I have no idea what this one is about," Storms said.
He was, however, sure of one thing: the light patching load users and administrators faced this month. "It's a 'where's the beef?' kind of month," he said. "Maybe we can all catch up a bit."