H3C HDM Family-A verifies the RSA signature of a firmware image against a public key it reads from the mutable file `/conf/public.pem`. That file is writable by an authenticated Redfish client through the `UpdateService.UploadSignKey` action, which stores the uploaded body verbatim after validating only that the multipart filename ends in `.pem`. An administrator, or any account with `firmware-update` privilege, can therefore replace the trust anchor with their own key, sign a malicious image wi