Microsoft delivers fix for critical Word vulnerability
For its October Patch Tuesday, Microsoft has published a total of seven security bulletins concerning 20 vulnerabilities in its Windows, Office, SQL Server and Lync products. One of the bulletins is rated "Critical", while the rest have been rated "Important" by the company.
Four of the bulletins concern security holes in Microsoft Office, the critical vulnerability being present in all versions of Word from Microsoft Office 2003 SP3 onwards. The vulnerability also affects SharePoint Server 2010 and Office Web Apps 2010. The hole is remotely exploitable if an attacker can get a user to open a specially crafted RTF file. This could lead to an attacker gaining the same system privileges as the current user.
An important vulnerability in the Windows kernel affects all currently supported versions of the operating system with the exception of Windows 8 and Windows 2012. The flaw can lead to a privilege escalation exploit when a user runs a specially crafted application, but the attacker needs to have a valid login on the system in question. This is due to a memory handling bug in the kernel that is fixed by the update.
The updates also fix several other remote code execution issues and a denial-of-service (DoS) vulnerability in the Kerberos authentication server. Exchange benefits from a fix to Microsoft's FAST Search Server that corrects file parsing problems related to Oracle's Outside In libraries. Similar vulnerabilities were already fixed in Microsoft's August Patch Tuesday.
As part of the update, Microsoft is now distributing a patch that declares Windows certificates invalid where the RSA private key is shorter than 1024 bits. This could lead to various problems including error messages while browsing, problems with S/MIME secure mail transport, and issues installing signed Active/X controls. If certificates with short RSA keys are in use, users of such keys should switch to a certificate with a sufficiently long RSA key. Microsoft has published an advisory explaining these ramifications.