The Cisco RV router firmware on RV220W devices, before 1.0.5.9 on RV120W devices, and before 1.0.4.14 on RV180 and RV180W devices allows remote attackers to upload files to arbitrary locations via a crafted HTTP request, aka Bug ID CSCuh86998.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.