This indicates an attack attempt to exploit an Authentication Bypass vulnerability in Micro Focus NetIQ Sentinel Server.
The vulnerability is due a flaw in SentinelContext Java class that allows a user to retrieve a valid authentication cookie from a vulnerable server. A remote attacker may be able to exploit this to bypass authentication and gain access to the web application as admin user, via a crafted HTTP request.
Micro Focus NetIQ Sentinel prior to 7.4.2
Security Bypass: Remote attackers can bypass security checks of vulnerable systems.
Apply the most recent upgrades or patches from the vendor.