@morlino - typically you paste your use of system-files and describe why you need the access. Looking in the store, I see cvescan is using:
plugs:
apt-dpkg-db:
interface: system-files
read:
- /var/lib/snapd/hostfs/var/lib/dpkg
- /var/lib/snapd/hostfs/var/cache/apt
- /etc/lsb-release
- /etc/apt
- /etc/dpkg
The interface reference and read-only access of hostfs and /etc make sense for this snap and what it needs to do. /etc/lsb-release is already in the default template and can be omitted.
+1 for use of and auto-connection of system-files using the above (after removing /etc/lsb-release).
@reviewers - can others please vote on this?