Path traversal vulnerability leading to an arbitrary file write in Western Digital devices

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability that could allow an attacker to write files to locations with certain critical filesystem types leading to remote code execution was discovered in Western Digital My Cloud Home, My Cloud Home Duo, SanDisk ibi and Western Digital My Cloud OS 5 devices. This issue requires an authentication bypass issue to be triggered before this can be exploited. 
This issue affects My Cloud Home and My Cloud Home Duo: before 9.4.0-191; ibi: before 9.4.0-191; My Cloud OS 5: before 5.26.202.