This indicates an attack attempt to exploit a Buffer Overflow vulnerability in CoolPDF.
The vulnerability is due to an error when the vulnerable software handles a maliciously 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.
CoolPDF 220.127.116.116 and possibly earlier versions.
System Compromise: Remote attackers can gain control of vulnerable systems.
Currently we are unaware of any vendor supplied patch or updates available for this issue.