From CIS scanning result"it should make sure the root's gid is equal to 0", so I don't know what's the impact for that change to whole system? BTW, why is there a group named other under solaris? what does group "other" do ?
You shouldn't cause too much trouble. Files in the "other" group could be inaccessible, depending on permissions but none of these should be system critical anyway. Personally, I wouldn't worry about making any changes as it doesn't matter if the root account has access to the group "others" anyway - it's easy enough for root users to gain access to any system/application data in any case, so it's not a security concern.
If you're really worried, run a find across your system, looking for everything with "other" group membership and see if anything you think is important shows up.
thanks for your explanation, I have a solution that may be better,
during OS start 3 level, call passmgmt -m -g 0 root to update root's gid, BTW, we should keep the other property, so we should call 'groups root' to query all root's groups, than call usermod -G result root to append the existing group. right?
I haven't found a better way to add some user into some group yet.