October’s 2009 Microsoft Patch Tuesday is a massive release with 13 advisories covering 34 vulnerabilities. 2 advisories address last month’s 0-day vulnerabilities – SMBv2 and FTP for IIS in a very quick turn-around. However another 6 vulnerabilities are tagged as having information disclosed publicly before today’s patch release. Of the total set of vulnerabilities a full 22 are of critical severity and should be addressed as quickly as possible. A large selection of software is affected: all versions of Windows (including Windows 7), Windows Media Player, Office and also Silverlight – Microsoft’s new rich media development tool. Internet Explorer also receives an update for 2 critical vulnerabilities – one of them disclosed at the Black Hat Security conference.
MS09-054 is a fix for critical vulnerabilities in all versions of Internet Explorer and interestingly can also affect non-Microsoft software – namely Firefox the browser from Mozilla. The Microsoft .Net runtime installs a plug-in into Firefox that allows XAML Browser Applications (XABP) to be launched through Firefox and serves as a conduit to the vulnerable component of Windows.
The biggest set of vulnerabilities this month is addressed by MS09-062, which fixes 8 flaws in the GDI+ graphics library. This library is widely used in applications as diverse as Microsoft Office, Visual Studio development tools, SQL Server and even Forefront Security Client.
Another set of 2 vulnerabilities disclosed at Black Hat (video presentation here and here – worth watching) is addressed by MS09-056. It provides a fix to the CryptoAPI library and the much talked about "Null prefix certificate" which allows for the impersonation of an arbitrary SSL certificate by embedding a NULL character at the right spot in the certificate request. Earlier this month a certificate was leaked to the full disclosure mailing list that impersonated www.paypal.com. The vulnerability is rated only as "important", because it does not allow the attacker to take over the machine, but it can be used to steal the user’s credentials to any web site.
Important: Adobe released their patch for Adobe Reader, the popular PDF viewer. Adobe Reader versions 7, 8 and 9 are vulnerable on all versions Windows and Mac OS X. Adobe had acknowledged the existence of exploits focused on v9 and Windows last week. This is a critical update that should be applied as soon as possible.