Getting "Forbidden" when trying to post replies

[aepaegayah]

Hello,

I have started a thread at viewtopic.php?t=7520; however, when attempting to post a reply, the server is saying that I do not have permission:

Forbidden

You don't have permission to access this resource.

Is this just some silly PEBKAC error?

[euler]

That is most peculiar. I'm not sure what is causing it. Maybe you could try refreshing the page and trying to post again or signing out and signing back in again? The other possibility is that your post contains something that the server security mod is not liking. You could try posting different parts of the post to see if you can identify which part is causing the problem.

It will be interesting to see if you can reply to this message.

[aepaegayah]

Taking a bit of a closer look, I seem to be hitting some case in the input sanitizer or something. A string that looks like a Request-Line of an HTTP request ends up triggering the Forbidden message when trying to submit or even preview a message.

For example, in the line below, replacing "<version>" with "1.1" or "2" triggers the error. Note, that the string doesn't even need to be isolated on its own line; it can be embedded within other text.

GET / HTTP/<version>