DNS Leak When Using Socks5 Proxy

[jimsmt]

Description

Brave is leaking local DNS when using socks proxy

Steps to Reproduce

1. Use the SwithcyOmega extension to set proxy to a local socks5 proxy
2. Vist https://browserleaks.com/dns to test

Actual result:

Results show that local DNS is leaked

Brave version (brave://version info)

Brave | 1.30.89 Chromium: 94.0.4606.81 (Official Build) (64-bit)
Revision | 5a03c5f1033171d5ee1671d219a59e29cf75e054-refs/branch-heads/4606@{#1320}
OS | Windows 10 Version 1809 (Build 17763.2237)

Other Additional Information:

• Is the issue reproducible on the latest version of Chrome?
  No, tested on latest version of Chrome and other Chromium based browsers

[jimsmt]

Also tested on latest lightly version: Nightly v1.33.6, same issue

[jimsmt]

By using wireshark to analyse traffic when using Brave browser with socks5 proxy, I found that Brave is sending UDP DNS lookup request directly to the server in my computer's DNS setting, which is very horrible, especially for a browser mainly focused on PRIVACY

[jimsmt]

I can confirm that this issue exists from version 1.17 to latest 1.33, version older than 1.16 doesn't have this problem

[rebron]

Hi @neeythann What do you have set for your DNS settings in brave://settings/security
Are you using a custom provider in that drop down list for DoH or something else?

[neeythann]

Hi @rebron , I believe the fix is already on #19070

[diracdeltas]

thanks, i will close as a dupe of #19070