Microsoft today said it will dispense five security updates next week to patch 15 vulnerabilities in Windows, Excel, SharePoint Server and Groove.
All five updates will be rated "important," the second-highest threat ranking in Microsoft's four-step system.
Microsoft usually ships a smaller number of updates in odd-number months, and kept to that plan today: September's volume is down from August's, when the company patched 22 vulnerabilities with 13 "bulletins," the word it uses to describe individual security updates.
"Not a lot there, but then we didn't expect much," said Andrew Storms, director of security operations at nCircle Security. "It is the light month, the down month."
Sorting out all the bugs
The company laid out the bare bones of the upcoming patches in an advanced notice of next week's Patch Tuesday.
Two of the updates affect Windows, with one of the pair impacting only the server editions: Server 2003, Server 2008 and Server 2008 R2. The second bulletin patches one or more bugs in all supported versions of the operating system, including the decade-old XP and the much newer Windows 7.
"There are a number of server-only components that have been present through the whole lifecycle [of Windows Server]," said Storms, referring to the server-only update, which Microsoft tagged as "Bulletin 1" today. "SMB [server message block] is an example. And they patched SMB often in the last several months."
SMB is a Microsoft-designed network and file-sharing protocol, and has been patched multiple times this year, including an April update that plugged a critical hole some analysts said might be used by criminals to construct a dangerous worm.
Another two updates next week will fix problems in Excel - including the newest Excel 2010 on Windows and Excel 2011 for the Mac - and in Office generally. The fifth will patch a variety of server-side software, including SharePoint, Groove and Office Web Apps, the cloud-based version of Microsoft's suite.
Patches to prevent attackers from executing remote code
Although Microsoft said that vulnerabilities to be patched in three of the upcoming bulletins could be used by attackers to execute remote code (meaning that successful exploits would let hackers hijack a machine), Microsoft's rankings offer a clue, said Storms.
"Because they rated them as only important, the attack scenarios probably will require user interaction," said Storms.
Microsoft usually ranks updates as important, not critical, when they patch remote code bugs that demand the user "help" the attacker by being tricked into visiting a malicious website.
Another security researcher urged Windows users not to get complacent next week just because there will be no critical updates.
"While 'important' vulnerabilities may not give attackers the full root privileges generally associated with 'critical' vulnerabilities, an attacker can use an important-rated vulnerability to achieve an initial compromise and then escalate privileges by other means," said Marcus Carey of Rapid7 in an email. "Attackers can still end up with the same result."
Storms also used the opportunity to note that Microsoft has not issued any emergency, or "out-of-band," updates this year. In 2010, Microsoft shipped four.
"If they close the year without any it would be a first," said Storms. "I think it's an indication of the mitigation efforts baked into their software. We know there are bugs in Microsoft software, but they've not been forced so far this year into going out of cycle to reduce risk."
The five updates will be released at approximately 5pm BST on 13 September.