[joe_bleau]

Testing the ssh client config workaround:

   ssh -v user@localhost 2>&1 >/dev/null | grep -i 'roaming'

returns "debug1: Roaming not allowed by server" when vulnerable, and nothing when not. YMMV, only tested on a few machines, etc.

[clort]

does this require a ssh server running on localhost?

[pmuk]

Yes, that command is connecting to an ssh server on localhost, but you could connect to any ssh server that you trust...

  ssh -v -T [e-mail] 2>&1 | grep -i 'roaming'