Light Patch Tuesday fixes 15 vulnerabilities

In today’s Patch Tuesday, Microsoft delivers 5 security bulletins (all rated “important”) that address 15 vulnerabilities affecting Windows, Microsoft Office and Microsoft Server Software.

In addition to that, Microsoft has also released updated security advisory and has added six more DigiNotar root certificates to its Windows Untrusted Certificate Store.

Vulnerability in WINS Could Allow Elevation of Privilege
This security update resolves a privately reported vulnerability in the Windows Internet Name Service (WINS). The vulnerability could allow elevation of privilege if a user received a specially crafted WINS replication packet on an affected system running the WINS service. An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability.

Vulnerability in Windows Components Could Allow Remote Code Execution
This security update resolves a publicly disclosed vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if a user opens a legitimate rich text format file (.rtf), text file (.txt), or Word document (.doc) that is located in the same network directory as a specially crafted dynamic link library (DLL) file. An attacker who successfully exploited this vulnerability could gain the same user rights as the local user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.

Vulnerabilities in Microsoft Excel Could Allow Remote Code Execution
This security update resolves five privately reported vulnerabilities in Microsoft Office. The vulnerabilities could allow remote code execution if a user opens a specially crafted Excel file. An attacker who successfully exploited any of these vulnerabilities could gain the same user rights as the logged-on user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Installing and configuring Office File Validation (OFV) to prevent the opening of suspicious files blocks the attack vectors for exploiting the vulnerabilities described in CVE-2011-1986 and CVE-2011-1987.

Vulnerabilities in Microsoft Office Could Allow Remote Code Execution
This security update resolves two privately reported vulnerabilities in Microsoft Office. The vulnerabilities could allow remote code execution if a user opens a specially crafted Office file or if a user opens a legitimate Office file that is located in the same network directory as a specially crafted library file. An attacker who successfully exploited either of the vulnerabilities could gain the same user rights as the logged on user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.

Vulnerabilities in Microsoft SharePoint Could Allow Elevation of Privilege (2451858) publicly disclosed vulnerability in Microsoft SharePoint and Windows SharePoint Services. The most severe vulnerabilities could allow elevation of privilege if a user clicked on a specially crafted URL or visited a specially crafted Web site. For the most severe vulnerabilities, Internet Explorer 8 and Internet Explorer 9 users browsing to a SharePoint site in the Internet Zone are at a reduced risk because, by default, the XSS Filter in Internet Explorer 8 and Internet Explorer 9 helps to block the attacks in the Internet Zone. The XSS Filter in Internet Explorer 8 and Internet Explorer 9, however, is not enabled by default in the Intranet Zone.