TL-WR845N(UN)_V4_201214, TP-Link TL-WR845N(UN)_V4_200909, and TL-WR845N(UN)_V4_190219 was discovered to transmit user credentials in plaintext after executing a factory reset.
TP-Link TL-WR845N(UN)_V4_190219 was discovered to transmit credentials in base64 encoded form, which can be easily decoded by an attacker executing a man-in-the-middle attack.