Home page logo

bugtraq logo Bugtraq mailing list archives

Re: syslog/udp
From: jhawk () panix com (John Hawkinson)
Date: Wed, 23 Feb 1994 06:55:21 -0500 (EST)

From: Dave Hayes <dave () elxr Jpl Nasa Gov>

Cc: no-more-secrets () primus COM, bugtraq () crimelab com
What is that, btw?

Tim Newsham <newsham () uhunix uhcc hawaii edu>

  If you are running syslogd on your machine and you dont receive
remote logging to that machine you should probably consider removing
the remote function of the program.

If this is not an option (because your terminal servers, routers,
widgets, all log to your loghost with udp syslog), you should
certainly consider screening syslog (514/udp) at your router,
anong with NFS and related things. There's no reason for you to
have to syslog across the 'Net.

Besides being another possible security risk a person may easily
corrupt your audit logs though this port.  It is quite easy to
send fake messages to the syslogd at any facility and level.  An

What exactly is the problem?

The problem is that syslogd will accept any message from anywhere
on the net. If you have to accept messages from your local net,
this fix is not useful -- if you're only logging things on your
local machine (i.e. all programs logging are using syslog(3)),
then you can disable logging over UDP.

How can we, who are without source code, change this behavior?

You can get the Berkeley syslogd code, which is in all likelyhood
compatible with your current syslogd.

Actually, thinking about syslogd I have a few questions:

1) What's the susceptibility of it to UDP-dropping? If someone's
going to do something they don't want logged, how easy will it
be to flood the net with packets and make your loghost drop
the packet-in-question. How easy without root? :-)

2) Is your syslogd running out of file descriptors? The last time
I ran syslogd with -d (debug), it seemed there were only 4 left.
Perhaps this is a SunOS peculiarity, but I suspect I'll have to
use the BSD syslogd soon, anyway, just because I need to log
more stuff...

John Hawkinson
jhawk () panix com

  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]