thunderbird cannot use socks proxy

[Lars Noodén]

Binary package hint: thunderbird

Thunderbird seems not to be able to use SOCK proxies even though they are listed as an option.
In some cases this means denial of access. In other cases it means choosing between and insecure network connection and denial of access. Firefox can use SOCKS5 proxies and Thunderbird has a very similar preferences dialog.

When configured with the same proxy settings that work just fine for Firefox, Thunderbird gives and error message:

"Failed to connect to server ...."

The proxy settings can be found:

Edit->Preferences->Advanced->Network&Disk Space->Connection->Manual Proxy Configuration->SOCKS ...

$ lsb_release -rd
Description: Ubuntu 9.10
Release: 9.10

$ apt-cache policy thunderbird
thunderbird:
  Installed: 2.0.0.23+build1+nobinonly-0ubuntu1
  Candidate: 2.0.0.23+build1+nobinonly-0ubuntu1
  Version table:
 *** 2.0.0.23+build1+nobinonly-0ubuntu1 0
        500 http://fi.archive.ubuntu.com karmic/main Packages
        100 /var/lib/dpkg/status

[Kees Cook (kees)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find.

[Lars Noodén (larsnooden)]

This is certainly a security bug. It may not need to be hidden from the world, but be assured that it is certainly a security bug.

[Lars Noodén (larsnooden)]

Looking some more, it looks like it is a matter of Thunderbird not proxying the DNS queries properly (or at all).

For Firefox, the following settings fix the problem:
  Preference Name Status Type Value
  network.proxy.socks_remote_dns user set boolean true

For Thunderbird, DNS lookup should go along by default with the proxy or at least have a visible checkbox on the proxy dialog.

[Lars Noodén (larsnooden)]

See this page for more about Firefox. It might be that the same option is missing from Thunderbird
http://kb.mozillazine.org/Network.proxy.socks_remote_dns

[Daniel Hahler (blueyed)]

You might want to try using "tsocks" for this - it will wrap thunderbird via dynamic library loading into using a SOCKS proxy.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sander Maijers (s-n-maijers)]

The issue affects me still with 45.8.0.

[CodeHike (gerardlevergen)]

also affects thunderbird 45.8.0 in zesty