MS12-077  Cumulative Security Update for Internet Explorer

2012-12-11 This security update resolves three privately reported vulnerabilities in Internet Explorer. The most severe vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. An attacker who successfully exploited these vulnerabilities could gain the same user rights as the current 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 addressed in this bulletin:

InjectHTMLStream Use After Free Vulnerability

A remote code execution vulnerability exists in the way that Internet Explorer accesses an object in memory that has been deleted. The vulnerability may corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user.
CVE-2012-4781

CMarkup Use After Free Vulnerability

A remote code execution vulnerability exists in the way that Internet Explorer accesses an object in memory that has been deleted. The vulnerability may corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user.
CVE-2012-4782

Improper Ref Counting Use After Free Vulnerability

A remote code execution vulnerability exists in the way that Internet Explorer accesses an object that has not been correctly initialized or has been deleted. The vulnerability may corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user.
CVE-2012-4787

Bulletin details at Microsoft.com