On Verizon 5G Home LVSKIHP InDoorUnit (IDU) 3.4.66.162 and OutDoorUnit (ODU) 3.33.101.0 devices, the CRTC and ODU RPC endpoints provide a means of provisioning a firmware update for the device via crtc_fw_upgrade or crtcfwimage. The URL provided is not validated, and thus allows for arbitrary file upload to the device. This occurs in /lib/lua/luci/crtc.lua (IDU) and /lib/functions/wnc_jsonsh/wnc_crtc_fw.sh (ODU).
CWE-434