Five switches in the panel you have never opened
The Sharing panel most Mac users have never opened, one switch at a time
👋 HEY, IT'S RAJA
Here is the news story from this week that you probably scrolled past.
On August 6, Apple pushed out-of-band updates for macOS Tahoe 26.6.1, Sequoia 15.7.9, and Sonoma 14.8.9. It fixed a flaw in Screen Sharing that let an attacker on the network authenticate without valid credentials. Six days later, the Dutch national cybersecurity center reported that the flaw was being actively exploited against Macs, with port 5 exposed to the internet. In every case they saw, attackers got root and installed a cryptocurrency miner. On August 14, CISA raised the severity score from 7.1 to 9.8, and proof-of-concept code is now public.
Before you panic: Screen Sharing is off by default, and a normal home router blocks that port from the outside anyway. This is a problem for people who deliberately opened a door at some point and forgot.
Which is a very good reason to spend ten minutes in a panel most Mac users have never opened. System Settings → General → Sharing. Five switches: what each one actually exposes and who should have it on.
1️⃣ Screen Sharing
This lets someone view your screen and control your keyboard and mouse remotely. This is the one from the news. If you are on macOS and have not installed the August 6 update, do so before you do anything else: go to System Settings → General → Software Update.
Who should have it on: people who genuinely work remotely on their own Mac. Everyone else, off. If you turned it on once to help a family member and never turned it back off, this is your moment.
2️⃣ Remote Login
Opens SSH access to your Mac. Powerful, completely legitimate, and far more capable than most people realize, because a shell is not a window into your Mac; it is the whole Mac.
Who should have it on: developers and anyone who knowingly SSHes into this machine. If you cannot say what SSH is, you do not need it on, and it should not be.
3️⃣ Remote Management
The heavier sibling of Screen Sharing, built for IT departments managing fleets of Macs. It can do considerably more than view your screen.
Who should have it on: people whose Mac is managed by an employer; in which case, leave it alone. On a personal machine, it should almost always be off.
4️⃣ File Sharing
Makes folders on your Mac reachable over the network. Handy on a home network, less handy when you are on hotel or café wifi.
Who should have it on: if you use it, keep it, but go into the options and check which folders you shared and who has access. That list tends to accumulate.
5️⃣ Media Sharing
Shares your music and media library with other devices on the network. The least dangerous of the five and the most likely to be on without your knowledge, because it gets switched on in passing during setup.
Who should have it on: anyone actually streaming their library to another device. Otherwise, it is one more service listening for no reason.
The bonus check that matters most
If any of the above are on and you want them reachable from outside your home, at some point you or someone else forwarded a port on your router. That forwarding is what turns a local convenience into an internet-facing service.
Log in to your router, find the port forwarding section, and review its contents. Most people find at least one rule they set up years ago for something they no longer use. Delete those. This is the single most valuable ten minutes on the list, and almost nobody does it.
Ten minutes, and most of you will find nothing wrong, which is the correct outcome. Next week, Apple should send out the September invitation, so things are about to get busy.
Keep it useful,
Raja · The Useful Tech
P.S. Enjoyed this? Forward it to a friend who loves their Apple gear a little too much.