Check it out:
brew search sshpass
We won't add sshpass because it makes it too easy for novice SSH users to ruin SSH's security.
Gee thanks Homebrew I'd be more than happy to use SSH as intended if I could... perhaps you'd like to go talk to the manufacturer of this ancient piece of hardware running a barebones busybox linux distro on my behalf.
In the meantime:
brew install chbrown/extra/sshpass