In a real attestation scheme you would do something like have the attesting device generate a hardware-backed key to be used for communications to and from it, to ensure it is not possible to use an attestation of one device to authenticate any other device or a man-in-the-middle. Usually for these devices you can verify the integrity of the hardware-backed key as well. Of course all of this is moot though if you can trick an authorized device into signing or encrypting/decrypting anything attacker-provided, which is where many systems fail.