Letters

I have enjoyed your guide to the Linux desktop series immensely, and I was delighted to see that you wrote about my favorite window manager, Window Maker. Of course, I wasn't too terribly happy with your lack of praise for my darling, but still, I don't want to start a holy/flame war. I merely wanted to inform you of one thing. —Robert Wade robertwade@rocketmail.com

I'm glad you liked the series. There is one more coming, which should be out in the next couple of months, that does basic coverage of the remainder of the window managers out there. —Michael J. Hammel mjhammel@graphics-muse.org

I know that exaggerating about how long one has been using Linux is a long-standing tradition for some people in the community, but it's getting a little out of hand.

In the June 2000 issue on page 98, the article claims that H. J. Lu discovered Linux in 1990. That's simply amazing, since Linus announced the project on July 3, 1991. (www.li.org/li/linuxhistory.shtml)

Perhaps Mr. Lu has the capability of seeing into the future? —Dave Whitinger dave@whitinger.net

I neglected to mention an important point in my article on syslogd in the July issue of Linux Journal: If you plan to use the network features of syslogd, it is very important that this port be behind a strong and properly configured firewall router. If not, the feature should not be used. The network syslogd interface is a great way to do remote denial of service attacks, and even some far more insidious attacks. The denial of service can be to both CPU and disk, since sending tons of spurious messages can make syslogd fill a disk drive. Moreover, such messages may be used to obscure other evil activities which you might lose in a flood of phony messages.

Even more frightening is the possibility that you are watching some log files with, say, poorly written Perl scripts that interpolate variables containing strings from syslog-generated log files. There are some clever Perl hacks where you can compose strings that will execute programs as the user running the script. Such strings could be embedded in fake messages sent to your syslog d<\#230;>mon.

The upshot of all this is that while collecting logs from multiple machines over a network is a very nice and useful feature, you must be sure to prevent machines outside your network from reaching this port.

This is an important point, and I hope you can find room for my letter! Thanks a lot!

Here is the corrected Listing 1 to include with my other comment.

Due to an accident of typesetting, the syslog.conf listing in the July 2000 issue was incorrect. The correct listing appears below.

Listing 1

—Michael A. Schwarz mschwarz@sherbtel.net