An issue was discovered in OpenWrt libuci (aka Library for the Unified Configuration Interface) before 15.05.1 as used on Motorola CX2L MWR04L 1.01 and C1 MWR03 1.01 devices. /tmp/.uci/network locking is mishandled after reception of a long SetWanSettings command, leading to a device hang.
git.openwrt.org/?p=project/uci.git%3Ba=commitdiff%3Bh=19e29ffc15dbd958e8e6a648ee0982c68353516f
github.com/TeamSeri0us/pocs/blob/master/iot/morouter/motorola%E8%B7%AF%E7%94%B1%E5%99%A8%E6%96%87%E4%BB%B6%E8%A7%A3%E9%94%81%E6%BC%8F%E6%B4%9E.pdf
lists.infradead.org/pipermail/openwrt-devel/2019-November/019736.html
lists.openwrt.org/pipermail/openwrt-devel/2019-November/025453.html