This is the most critical feature of this patch. It addresses multiple critical vulnerabilities and security loopholes discovered in previous versions of Acrobat 11.x. Without this update, the software is susceptible to arbitrary code execution, memory corruption, and "use-after-free" attacks that could allow an attacker to take control of the system via a malicious PDF file.
If you have received or downloaded this file and are looking to apply the update: acrobatupd11023.msp