It was bumped to the home page by the Community User as an old question with no answers at a positive score. The point of bumping is to reassess the quality of the question and its answers.
On balance, it looked too localized to me, had a very low number of views after 1 year and 8 months, no votes, and the author has never responded to your questions or even interacted with the site again - so I closed it.
I think security system configuration issues can actually be very relevant to DBAs. But maybe that's just me?
Some security system configuration issues will be on topic, but that doesn't mean all are, and not all on-topic questions are suitable for the long-term.
That said, as a user with the close and reopen privilege you may vote to reopen it if you think it is on-topic and has lasting value to the site. That will start a reopen review process where other community members with that privilege can assess the merits of reopening.