This indicates an attack attempt against a Directory Traversal vulnerability in ManageEngine Netflow Analyzer and IT360.
The vulnerability is due to insufficient sanitizing of user supplied inputs when handling a crafted HTTP packet. It allows a remote attacker to download arbitrary files from vulnerable machine via crafted requests.
ManageEngine IT360 10.4 and prior
ManageEngine NetFlow 10.2 and prior
Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems.
Currently we are unaware of any vendor supplied patch for this issue