A remote code execution vulnerability exists in RPC if the server has Routing and Remote Access enabled. An attacker who successfully exploited this vulnerability could execute code on the target system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
To exploit this vulnerability, an attacker would need to run a specially crafted application against an RPC server which has Routing and Remote Access enabled. Routing and Remote Access is a non-default configuration; systems without it enabled are not vulnerable.
The security update addresses the vulnerability by correcting how the Routing and Remote Access service handles requests.