This indicates an attack attempt to exploit a remote Code Execution Vulnerability in Linksys E-series Router.
It is exploited by TheMoon worm.
The vulnerability is due to a error in failing to properly sanitized user input from a HTTP request. A remote attacker could exploit this to execute arbitrary code execution within the context of the application, via a crafted HTTP request.
System Compromise: Remote attackers can gain control of vulnerable systems.
Currently we are unaware of any vendor supplied patch for this issue.