This indicates an attack attempt to exploit a Buffer Overflow vulnerability in Adobe Acrobat and Reader.
The vulnerability is due to an improper boundary check condition in the application when handling a crafted PDF file. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted PDF file.
Adobe Reader XI (11.0.03) and prior 11.x versions
Adobe Reader X (10.1.7) and prior 10.x versions
Adobe Acrobat XI (11.0.03) and prior 11.x versions
Adobe Acrobat X (10.1.7) and prior 10.x versions
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.