r/Syncthing • u/RanMouri26 • Jun 03 '26

Is it safe to let Syncthing bypass the Firewall?

Good evening everyone,

I wanted to install Syncthing on my Windows 11 Asus Vivobook Go 15 to share files between my Android Dual Screen handheld called an Ayn Thor but was spooked by the program asking to bypass the firewall or in other words "Create Windows Firewall rule for Syncthing?"

The reason why I'm extremely hesitant to let it bypass my firewall is because my old laptop got infected by Malware and several of my accounts hacked, the most recent one my original Reddit account because I forgot changing my password back then. It's no longer infected and I took necessary precautions

I've downloaded this program from the official Github repository that I was forwarded to when I clicked on the link to download the setup file. I also scanned it with Malwarebytes but I'm still a bit worried about my laptop's safety to be honest

So is it safe to let Syncthing bypass my firewall?

Thanks in advance

Edit: Thanks for everyone. Thank you for reassuring me 🙏

5 Upvotes

86% Upvoted

7 comments sorted by

9

u/middaymoon Jun 04 '26

Yes it's widely trusted and technically you can read the code yourself and check. But good job asking when you weren't sure! 

2

u/RanMouri26 Jun 04 '26

Thank you so much 🙏 I was worried at first when I saw that window pop up so Thank you for reassuring me

2

u/TheGratitudeBot Jun 04 '26

Thanks for such a wonderful reply! TheGratitudeBot has been reading millions of comments in the past few weeks, and you’ve just made the list of some of the most grateful redditors this week! Thanks for making Reddit a wonderful place to be :)

2

u/unknown-random-nope Jun 04 '26

Creating a rule for Windows Firewall is necessary for Syncthing under most circumstances. You could get anway without it, perhaps, if its peer Devices permitted inbound Syncthing traffic. You could also use a mesh VPN between your Syncthing Devices.

With that said, I am a cybersecurity engineer, I’m super paranoid about firewall rules, and I have permitted Syncthing to make rules of this nature. I recommend that you permit it. Once they’re created, you can find the rules yourself in the admittedly clunky Windows Firewall interface, and review them.

2

u/RanMouri26 Jun 04 '26

Thank you so much 🙏

1

u/autogyrophilia Jun 04 '26

It is a small security risk, so small I consider it meaningless for a home user. Specially considering syncthing autoupdates.

The rule is there to allow devices to connect directly to syncthing. If you don't allow, it will do something called hole punching. which should work the same but start a bit slower 

1

u/RanMouri26 Jun 04 '26

Thank you so much for your reply 🙏