Provide your large home with fast, reliable, and secure wireless internet access using the TP-Link Archer AX21 AX1800 Wireless Dual-Band Gigabit Router. With this 802.11ax dual-band router, you can transfer data wireless at up to 1775 Mb/s over the 2.4 GHz and 5 GHz frequencies for smooth 4K video streaming, online games, video chats, and more.
Researcher Voyag3r from exploi-db website has found then this router is part of vulnerability.
The bug itself is an unauthenticated command injection vulnerability in the locale API available via the web management interface. This endpoint allows a user to specify the form we want to call by specifying the query string form along with an operation, which is usually read or write.
TP-Link advice to apply upgrade firmware from the web, as soon as possible.
More details you can find in this link