A partial authentication bypass vulnerability exists on Realtek RTL8812AR 1.21WW, RTL8196D 1.0.0, RTL8192ER 2.10, and RTL8881AN 1.09 devices. The vulnerability allows sending an unencrypted data frame to a WPA2-protected WLAN router where the packet is routed through the network. If successful, a response is sent back as an encrypted frame, which would allow an attacker to discern information or potentially modify data.