This indicates a possible attack against a Command Injection vulnerability in Linksys WAG54G2.
The vulnerability is due to insufficient sanitizing of user supplied inputs in the application when parsing HTTP requests. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted HTTP request.
Linksys Wireless-G ADSL2+ Gateway WAG54G2 1.0.10
System Compromise: Remote attackers can execute arbitrary code on vulnerable systems.
Currently we are unaware of any vendor supplied patch or updates available for this issue.