The security holes, described in five critical and four important bulletins, affect multiple products, including Windows, Internet Explorer, Exchange, SQL Server and Office. In the worst-case scenarios, exploits could give attackers control of affected systems.
The first critical bulletin, labeled MS12-060, involves Windows Common Controls vulnerabilities, which affect Office, SQL Server, other server products and developer tools.
There have been "limited, targeted attacks" to try to exploit this security hole, but no public proof-of-concept code has been made available to Microsoft's knowledge, wrote Microsoft security official Yunsun Wee in a related blog post.
If a user visits a website that contains "specially crafted content" designed to exploit the vulnerability, attackers could execute code remotely on the affected machine. However, users would have to be tricked into visiting such a website. The malicious code can also be sent as an email attachment, but users would need to open the attachment for the attack to work.
Affected products include all supported editions of Office 2003, Office 2007, Office 2010 (except x64-based editions), SQL Server 2000 Analysis Services, SQL Server 2000 (except Itanium-based editions), SQL Server 2005 (except Microsoft SQL Server 2005 Express Edition, but including Microsoft SQL Server 2005 Express Edition with Advanced Services), SQL Server 2008, SQL Server 2008 R2, Commerce Server 2002, Commerce Server 2007, Commerce Server 2009, Commerce Server 2009 R2, Microsoft Host Integration Server 2004 SP 1, Visual FoxPro 8.0, Visual FoxPro 9.0 and Visual Basic 6.0 Runtime.
Microsoft patched a Windows Common Control bug in April that "made everyone sit up and take notice" due to the broad scope of important products it touched, said Andrew Storms, director of security operations at enterprise security vendor nCircle.
"There is some good news this month: that the attack vector associated with the [Windows Common Control] patch is an RTF (rich text format) file, and the victim has to explicitly open the file to allow the exploit. If you can't get this patch rolled out or mitigation applied quickly, you should remind users about the dangers of opening attachments from unknown persons," he said via email.
The second critical bulletin, labeled MS12-052, concerns four issues with IE that aren't known to be under "active attack." If successfully exploited, a malicious hacker could execute code on the affected machine with the privileges of the current user. As with the previous hole, users would need to visit a malicious Web page to fall victim to the attack. This vulnerability is rated critical for IE 6, IE 7, IE 8 and IE 9 on Windows clients and moderate for those same IE versions on Windows servers.
"It's the third month in a row with a new Internet Explorer patch, so Microsoft is really taking advantage of the new ability to release an IE patch more frequently. This probably means there are a lot more IE patches in our collective future, since it's a good bet Microsoft will be tackling their IE backlog post haste," Storms said.
The third critical bulletin, labeled MS12-054, involves three holes in Windows Networking Components related to the Remote Administration Protocol (RAP) and one issue affecting the Print Spooler. The vulnerabilities could allow malicious hackers to launch denial-of-service attacks and execute code remotely on the affected machine, among other scenarios. Microsoft hasn't received reports that these holes have been exploited.