Bug 97931

Summary:	LibreOffice looks up local hostname in DNS, leading to performance problems and security issues.
Product:	LibreOffice	Reporter:	DonJaime
Component:	LibreOffice	Assignee:	Not Assigned <libreoffice-bugs>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	aron.budea, giuseppe.castagno
Priority:	medium
Version:	5.0.4.2 release
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
Crash report or crash signature:		Regression By:

Description DonJaime 2016-02-17 11:21:13 UTC

User action: open LibreOffice with and without a network connection, and with connections to various networks, with various different DNS servers and varying proxy setups. 

Result: LibreOffice takes between less than 1 and 45 seconds to start up, depending which network the computer is connected to. The quickest startup comes with no network connection.

Expected result: LibreOffice should start up quickly regardless of the network context.

Workaround: add the local hostname to the system hosts file with address 127.0.0.1

Conclusion: LibreOffice is trying to find the host address by looking up the hostname in the DNS.

This is a Bad Idea. It wastes time and it's completely unnecessary. Under some circumstances revealing the hostname to the Internet like this could have security implications.

Comment 1 Aron Budea 2016-07-30 21:01:01 UTC

I'm not a network specialist, but based on your description the one logical conclusion is that all systems should have localhost set up properly in their hosts file. Can you give some reference on what the alternatives that could be used for looking up localhost are? Thanks!

Comment 2 DonJaime 2016-08-01 08:12:03 UTC

Not 'localhost'. The local hostname, different for each computer. Proper setup does not require it to be in the hosts file.

Comment 3 Aron Budea 2016-08-02 09:48:13 UTC

Okay, could you point to resources that detail what the application should be doing instead?

Comment 4 DonJaime 2016-08-02 10:28:11 UTC

"resources"?

In the original bug report I provided evidence that LibreOffice was doing something pointless, inconvenient, and possibly harmful, presumably in order to try to find the IP address of the computer it's running on.

I don't know why it was trying to do that, so I don't know what should be doing.

Comment 5 Aron Budea 2016-12-17 23:17:24 UTC

Just saw a bug report this is a duplicate of, my bad.

*** This bug has been marked as a duplicate of bug 47179 ***