This indicates an attack attempt to exploit a remote Command Execution vulnerability in Cisco Adaptive Security Appliance.
The vulnerability is due to insufficient sanitizing of user supplied inputs in the application. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted request.
Cisco ASA 5500 Series Adaptive Security Appliances
Cisco ASA 5500-X Series Next-Generation Firewalls
Cisco PIX Firewalls
Cisco Firewall Services Module (FWSM)
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.