This indicates an attack attempt to exploit a Buffer Overflow vulnerability in Rockwell Automation RSLinx Classic.
The vulnerability is caused by an error when the vulnerable software handles malformed CIP packet. It allows a remote attacker to crash vulnerable systems via sending a crafted packet to port 44818.
RSLinx Classic Versions 4.00.01 and prior.
System Compromise: Remote attackers can gain control of vulnerable systems.
Refer to vendor website for suggested workaround.