In F5 BIG-IP PEM 12.1.0 through 12.1.2 when downloading the Type Allocation Code (TAC) database file via HTTPS, the server's certificate is not verified. Attackers in a privileged network position may be able to launch a man-in-the-middle attack against these connections. TAC databases are used in BIG-IP PEM for Device Type and OS (DTOS) and Tethering detection. Customers not using BIG-IP PEM, not configuring downloads of TAC database files, or not using HTTP for that download are not affected.