Incorrect access control in the Maintenance module of D-Link DSL-7740C with firmware DSL7740C.V6.TR069.20211230 allows authenticated attackers with low-level privileges to arbitrarily change the high-privileged account passwords and escalate privileges.
https://www.dlink.com/en/security-bulletin/
https://gist.github.com/stevenyu113228/da01c377030fd8c92274feca54661202