This indicates an attack attempt to exploit a memory corruption vulnerability in Adobe Flash player.
The vulnerability is due to an error after Adobe Flash plug-in is unloaded. This vulnerability affects only the Safari and Opera web browsers. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application.
Adobe Flash Player 11.9.900.152 and prior versions
Adobe Flash Player 184.108.40.2067 and prior versions for Linux
Adobe AIR 220.127.116.110 and prior versions for Windows and Macintosh
Adobe AIR 18.104.22.1680 and prior versions for Android
Adobe AIR 22.214.171.1240 SDK and prior versions
Adobe AIR 126.96.36.1990 SDK & Compiler and prior versions
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.