This indicates an attack attempt to exploit a Integer Overflow vulnerability in Adobe Flash Player.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted SWF file. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted SWF file.
Adobe Flash Player Desktop Runtime 188.8.131.52 on Windows and Macintosh
Adobe Flash Player for Google Chrome 184.108.40.206 on Windows, Macintosh, Linux and Chrome OS
Adobe Flash Player for Microsoft Edge and Internet Explorer 11 220.127.116.11 on Windows 10 and 8.1 1
Adobe Flash Player for Linux 18.104.22.1684 on Linux
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.