CVE-2018-12257
An issue was discovered on Momentum Axel 720P 5.1.8 devices. There is Authenticated Custom Firmware Upgrade via DNS Hijacking. An authenticated root user with CLI access is able to remotely upgrade firmware to a custom image due to lack of SSL validation by changing the nameservers in /etc/resolv.conf to the attacker’s server, and serving the expected HTTPS response containing new firmware for the device to download.
Source: CVE-2018-12257