This indicates an attack attempt to exploit a Buffer Overflow vulnerability in Netmechanica NetDecision HTTP Server.
The vulnerability is due to an improper boundary check condition in the application when handling an overly long uri. As a result, a remote attacker can exploit this to execute arbitrary code within the context of the application or possibly cause a denial of service condition.
Netmechanica NetDecision 4.5.1 and earlier versions
System Compromise: Remote attackers can gain control of vulnerable systems
Apply the most recent upgrade or patch from the vendor.