I’ve looked into the linked security vulnerability (CVE-2019-2215). There various ready-to-use POCs for it, including a fully working “pop me a root shell” feature. Source code is also available.
Sadly the specific kernel version running on the current firmware (8901.2.A.0096.20191001, September patch level) is 4.9.112-perf+. The 4.9 kernel branch was patched some time ago. So this one is not a solution for us. Confirmed it by trying all the available POCs.