This module uses a blind SQL injection (CVE-2020-5724) affecting the Grandstream UCM62xx IP PBX to dump the users table. The injection occurs over a websocket at the websockify endpoint, and specifically occurs when the user requests the challenge (as part of a challenge and response authentication scheme). The injection is blind, but the server response contains a different status code if the query was successful. As such, the attacker can guess the contents of the user database. Most helpfully, the passwords are stored in cleartext within the user table (CVE-2020-5723). This issue was patched in Grandstream UCM62xx IP PBX firmware version 1.20.22.
To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':
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