This indicates an attack attempt against a Buffer Overflow vulnerability in multiple HTTP servers.
The vulnerability is due to insufficient sanitizing of user supplied inputs in the application when handling crafted HTTP requests. A remote attacker may be able exploit this to execute arbitrary code within the context of the application or possibly cause a denial of service condition.
Disk Pulse Enterprise 9.0.34
VX Search Enterprise 9.0.26
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the individual vendors.
Monitor the traffic from that network for any suspicious activity.