An exploitable improper access control vulnerability exists in the iw_webs account settings functionality of the Moxa AWK-3131A firmware version 1.13. A specially crafted user name entry can cause the overwrite of an existing user account password, resulting in remote shell access to the device as that user. An attacker can send commands while authenticated as a low privilege user to trigger this vulnerability.
https://talosintelligence.com/vulnerability_reports/TALOS-2019-0955