Hongdian H8922 3.0.5 devices have an undocumented feature that allows access to a shell as a superuser. To connect, the telnet service is used on port 5188 with the default credentials of root:superzxmn.

Hongdian H8922 3.0.5 devices allow OS command injection via shell metacharacters into the ip-address (aka Destination) field to the tools.cgi ping command, which is accessible with the username guest and password guest.

Hongdian H8922 3.0.5 devices allow the unprivileged guest user to read cli.conf (with the administrator password and other sensitive data) via /backup2.cgi.

Hongdian H8922 3.0.5 devices allow Directory Traversal. The /log_download.cgi log export handler does not validate user input and allows a remote attacker with minimal privileges to download any file from the device by substituting ../ (e.g., ../../etc/passwd) This can be carried out with a web browser by changing the file name accordingly. Upon visiting log_download.cgi?type=../../etc/passwd and logging in, the web server will allow a download of the contents of the /etc/passwd file.