783178 - socks_remote_dns=true leaks DNS (in some conditions)

Status: UNCONFIRMED

(Core :: Networking: Proxy, defect, P3)

Description

[lzdn]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:14.0) Gecko/20100101 Firefox/14.0.1
Build ID: 20120713225548

Steps to reproduce:

Firefox 14.0.1 x64 Linux
I was testing socks5 proxy + DNS resolving with wireshark.

Test method:
0. Change proxy, exit firefox and launch firefox again;
1. Open wireshark and start capture on eth adapter;
2. Enter 'dns' in filter bar;
3. In firefox, navigate to any url, repeat several times;
4. Stop capture and check the result.
   There should be not dns packet for previous visited urls.

Settings:
Only one socks5 proxy is set.
network.proxy.no_proxies_on: doesn't include 127.0.0.1, or the remote socks5 server
network.proxy.socks_remote_dns=true
network.prefetch-next=false


Actual results:

With proxy=127.0.0.1:port, DNS always leaked.
With proxy=remote-domain:port, DNS leakage was not observed.


Expected results:

socks_remote_dns=true doesn't leak DNS.

Comment 1

[Josh Matthews [:jdm]]

This sounds like the same problem identified in bug 751465.

Comment 2

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 3

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

In the process of migrating remaining bugs to the new severity system, the severity for this bug cannot be automatically determined. Please retriage this bug using the new severity system.

Comment 5

[BMO Automation]

Moving bug to Core/Networking: Proxy.