Avast firewall blocking Bash Ubuntu on Windows 10

Avast is blocking the new bash Ubuntu on Windows 10 Preview.
Disabling the firewall, Ubuntu files can be updated and internet is available.

I cannot add C:\Windows\System32\conhost.exe or C:\Windows\System32\bash.exe into the app settings of the firewall (don’t know why).

All my “other” firewall settings are “allowing” everything…
Seems like a “proxy” or “Friends” settings issue.

Please, help!

Thanks for reporting, we will look at this.

The whole unix subsystem is new in the windows world (last time we saw it was on NT4 with OS/2) we have to check what are the paths for packets from the new subsystem. Apparently they are different to the standard ones.

Thanks again, I will update you here.

Thanks for the pointer - I was able to add C:\Windows\System32\bash.exe allow all in/out as a packet rule which did the job for me.

Bash on Ubuntu for Windows get a new update in last Windows Insider Preview 14332.
But Avast is still blocking it.
Lukas, can you get a look on this?

Bump ???
Any news?

Just installed win 10 upgrade and installed the linux subsystem. I have tested and am sure it is your firewall blocking apt-get and other network traffic from the subshell.

How did you do it? I’m also having the same issues and can’t add it in application rules

It has been confirmed on the official Microsoft’s git repository that Avast causes the issue:

https://github.com/Microsoft/BashOnWindows/issues/718

Uninstalling Avast allows to run bash.

You don’t have to uninstall. Just pause the firewall while using bash. Of course, this is a workaround not a solution.

I disagree. I am only using avast antivirus (not the firewall component) and just disabling it is not enough, it needs to be uninstalled.

(EDIT: I am using the latest version)

Avast Free Antivírus should not block any connection, it’s not a firewall. Besides, I’m using the Premier version and just disabling the firewall is enough.
Which firewall do you use?
Sometimes, the interaction between Avast and other product is bringing the error.

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Hi, thanks for your response. I dont think I am the only one having this problem. I am using Windows 10 Firewall Control, which is a wrapper on the native windows firewall.

It is also mentioned in these links:
https://github.com/Microsoft/BashOnWindows/issues/565
https://github.com/Microsoft/BashOnWindows/issues/718

Tarkio, can you be more specific on your problems? Do you also have problems with programs connecting to the network from inside WSL, such as wget, or do you have problems installing the subsystem (as mentioned on the links you’ve posted) ? Thanks.

I cannot install the subsystem, it hangs after extracting the filesystem, as in the links I have posted. I tried that with avast disabled, but nothing changed. Same with another machine of the same configuration, but when I uninstalled avast free I was able to install WSL. Unfortunately I will not have access to that machine for the next 2 weeks, if you need more details.

Thanks a lot. Interesting as it goes well here with avast free on the box.

And Premium too, I have no issues installing/uninstalling bash.
My problem is on using “git” and “repo sync” commands.

Same issue here, unable to extract the filesystem while Avast! Free is installed.

I uninstalled Avast! and let it finish installing, then re-installed Avast, however now it will not connect (Just gives me an empty terminal that I can type in and nothing happens).

Without Avast! Free installed it logs in and lets me correctly use the feature.

Note: Disabling the service or the shields is not enough. It has to be fully uninstalled.

Ok, I surrender.
As I’m not using Avast Free I can’t say why the Premier version is working and the Free one is not.
By the way, all this are workarounds, we really want a final solution to keep Avast on and use Ubuntu bash in Windows 10.

I am running Avast Free 12.2.2276 on Windows 10 Anniversary Update and having the same problem as tarkio has - “lxrun /install” hangs on ‘extracting filesystem’. Stopping the Avast service does not resolve the issue.

Same problem in Avast IS 12.2.2276.