Kasa EC71 v4 and EC70 v4 firmware contains a static cryptographic private key stored in a read-only filesystem that is shared across devices.  An attacker with access to the firmware image can extract the embedded key.  Successful exploitation may allow an unauthenticated attacker on the same network to use this key in the web management service, compromising the confidentiality of encrypted communications. This may enable passive decryption of traffic or active man-in-the-middle (MITM) attacks