Paessler PRTG Network Monitor contains a local file inclusion vulnerability that allows a remote, unauthenticated attacker to create users with read-write privileges (including administrator).
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
A webserver component in Paessler PRTG Network Monitor 19.2.50 to PRTG 20.1.56 allows unauthenticated remote command execution via a crafted POST request or the what parameter of the screenshot function in the Contact Support form.