Security update resolves a privately reported vulnerability in the Windows Bluetooth Stack. The vulnerability could allow remote code execution if an attacker sent a series of specially crafted Bluetooth packets to an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. This vulnerability only affects systems with Bluetooth capability. This security update is rated Critical for all supported editions of Windows Vista and Windows 7. For more information, see the subsection, Affected and Non-Affected Software, in this section.
Source: https://thehackernews.com/2011/07/microsoft-vulnerability-in-bluetooth.html