This indicates an attack attempt against an integer overflow vulnerability in Helix DNA Server.
The vulnerability is caused by an error when the vulnerable software handles DESCRIBE request. It allows a remote attacker to execute arbitrary code via sending a specially crafted DESCRIBE request with an overly long, invalid LoadTestPassword field.
Real Networks Helix DNA Server 11.1
Real Networks Helix DNA Server 11.0
System Compromise: Remote attackers can gain control of vulnerable systems.
Update to version 11.1.3 or later.