Mea Culpa, Mea Proxy

Mea Culpa, Mea Proxy by pendragon David Whelan I just wrapped up what is probably just the next stage in an ongoing learning process of fail and fix! I run a number of technology products that I try to know well enough so that (a) they do what I want and (b) they don’t do things I don’t want, especially so far as that impacts others. This includes blocking spammers from using my e-mail server for relays, etc. So you can imagine my chagrin when first last week and then again this I received phone calls from fellow Netizens who received spam e-mails that showed they’d come from my IP address The first call twigged me to a problem that someone was using my IP address to send spam.  At first, after turning off the servers and my Internet connection and testing the configuration using open relay tools, looking at logs, etc., it seemed to have been a case of being spoofed.

But the second call made me wonder what else could possibly be causing it, because I was as certain as I could be that I wasn’t enabling open relay of messages.  A quick search using Google showed that my IP address was listed by some open proxy sites and that this was the relay problem:  not the e-mail server, but an open Apache Web server proxy. 

After a quick read of the Apache documentation on mod_proxy and the proxy functions I was using to enable my Apache Web server to talk to my Plone server, I figured out what the problem was.  [For Plone/Apache users, there’s some excellent documentation].  It’s obvious to the seasoned, I’m sure, but I hadn’t realized it when I’d first set up the server and the problem hadn’t surfaced for a number of years.

It made me realize some obvious ongoing maintenance issues:

  • that, once installed, I need to keep testing and poking at systems that seem to otherwise be fine.  Had I accessed some of the open proxy utilities, like those at Rosinstrument.com or the European IRC network, I could have tested the proxy and seen that it was “open”.
  • I need to create some sort of quick inventory of proxy, relay, and other functions that are available within any product I install, even if that isn’t something I’m going to use on my network.  It’s the same line of thinking, I suppose, as turning off the unnecessary default services/functions when you install any operating system or hardware.

So, my apologies if you were one of those affected by a message emanating through my site.  And to the exercised Englishman who called, if you’ll e-mail me your phone number, I’ll apologize in person!

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