Severity Rating: Critical
Revision Note: V1.1 (December 16, 2015): Bulletin revised to further clarify the steps users must take to be protected from the vulnerability described in CVE-2015-6161. This bulletin, MS15-124, provides protections for this issue, but user action is required to enable them; the cumulative update for Internet Explorer does not enable the protections by default. Before applying the protections, Microsoft recommends that customers perform testing appropriate to their environment and system configurations.
Summary: This security update resolves vulnerabilities in Internet Explorer. The most severe of the vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. An attacker who successfully exploited the vulnerabilities could gain the same user rights as the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.