An Incorrect Symlink Follow vulnerability exists in multiple Yottamaster NAS devices, including DM2 (version equal to or prior to V1.9.12), DM3 (version equal to or prior to V1.9.12), and DM200 (version equal to or prior to V1.2.23) that could be exploited by attackers to leak or tamper with the internal file system. Attackers can format a USB drive to ext4, create a symbolic link to its root directory, insert the drive into the NAS device's slot, then access the USB drive's symlink directory mounted on the NAS to obtain all files within the NAS system and tamper with those files.