This indicates an attack attempt to exploit a Remote Code Execution vulnerability in D-Link DIR-866L.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted request. Successful exploitation can result in arbitrary code execution on the application.
D-LINK DIR-866 REV-A 1.03b04
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.