There is a new a new vunerability discovered with Samba it affects versions 3.5 (released March 1, 2010) and onwards, the defacto standard for providing Windows-based file and print services on Unix ... Update Your NAS Server - There is a Vunerability in Samba
unRAID also have a patch out which silently addresses this https://forums.lime-technology.com/topic/57599-unraid-os-version-635-stable-release-available/