Error While Previewing PMs

[OMG PONIES]

I don't know if anyone can help me, but I've been getting the following error when trying to preview a PM before sending:

"Forbidden

You don't have permission to access /forums/private.php on this server.

Apache/2.2.3 (Red Hat) Server at www.giantitp.com Port 80"

Also, the title of the window says "403 Forbidden."

Technical details:
Mac OS X 10.6.7
Browser: Google Chrome 11.0.696.57 (also get the error in Mozilla Firefox 3.0.5).

Does anyone know why I'm getting this? Is it a server-side problem?

[Mando Knight]

Could be an issue with your content. No lynxes were harmed in the PM, were they?

[OMG PONIES]

Actually, one was mentioned, but in the context of "what is that, something like a bobcat or a mountain lion?"

Why would mentioning one block my post?

[Douglas]

Lynx is the name of a particular web server program that I'm not really clear on the purpose of. The 5 character sequence "lynx " (note the space) as part of a packet sent to a server can be an attempt to exploit this program to try to hack the server. Giantitp's hosting service has a security filter in place to block that, so any post or PM that contains "lynx " will get that "forbidden" error page instead of working. It's a completely pointless filter in this case because this site's server doesn't use that program, but the hosting service doesn't have an easy way to customize or disable the filter.

If you want to talk about lynxes on this site, you have to follow the word with something other than a space or break it up with spurious formatting tags. For example, the reason my post worked despite saying "lynx " several times is that each time there's a meaningless color=black tag in the middle of the word (I put it on the n).

[OMG PONIES]

Ah, interesting. ty.

[Zherog]

If I recall correctly, the word "to" followed by a colon followed by two spaces will also cause the issue.