An elevation of privilege vulnerability exists in Windows Audio Service when a malformed parameter is processed. An attacker who successfully exploited the vulnerability could run arbitrary code with elevated privileges when used in conjunction with another vulnerability.
To exploit the vulnerability, an attacker could run a specially crafted application locally. This vulnerability by itself does not allow arbitrary code to be run. However, this vulnerability could be used in conjunction with one or more vulnerabilities (e.g. a remote code execution vulnerability and another elevation of privilege) that could take advantage of the elevated privileges when running.
The update addresses the vulnerability by correcting how the Windows Audio Service handles these parameters.