Improper Authorization vulnerability of Pepperl+Fuchs P+F Comtrol RocketLinx ES7510-XT, ES8509-XT, ES8510-XT, ES9528-XTv2, ES7506, ES7510, ES7528, ES8508, ES8508F, ES8510, ES8510-XTE, ES9528/ES9528-XT (all versions) use undocumented accounts.
https://cert.vde.com/de-de/advisories/vde-2020-040
http://seclists.org/fulldisclosure/2022/Jun/3
http://seclists.org/fulldisclosure/2021/Jun/0
http://packetstormsecurity.com/files/167409/Korenix-JetPort-5601V3-Backdoor-Account.html