An information disclosure vulnerability exists in the way Windows DirectShow handles objects in memory. An attacker who successfully exploited the vulnerability could obtain information to further compromise a target system.
In a web-based attack scenario, an attacker could host a website used to attempt to exploit the vulnerability. Additionally, compromised websites and websites that accept or host user-provided content could contain specially crafted content that could be used to exploit the vulnerability. However, in all cases, an attacker would have no way to force users to view attacker-controlled content. Instead, an attacker would have to convince users to take action. For example, an attacker could trick users into clicking a link that takes them to the attacker's site.
The security update addresses the vulnerability by correcting how Windows DirectShow handles objects in memory.