PHP Patch

You would have to recompile the 'openssl' extension for your version of PHP.  It would require you to have the same compiler that was used to create your version.  Your hosting company should have taken care of this already.  Call them and find out what the status is.

I have an unmanaged server, this is the first time I have come across an issue like this

The link you posted is to the people who would create the patch.  I don't think you're going to go buy the compiler and learn how to use it for this patch.  On my Ubuntu machines here at home, I get patches thru the Update Manager when they're available.  You would also have to get the source code for that extension so you could compile it.

Why do you think you need this patch?  The patch is exactly what you see on that page.

And that is Just the patch.  You would also have to get the complete source code for that extension to re-compile it with the patch.

I need the patch because Plesk updated yesterday and it has broken Horde, if you try to login to webmail you get "Mail server closed the connection unexpectedly." The patch appears to resolve this issue

The only people who might have a binary copy of the patched extension would  be the people provided your version of Linux and PHP.  I still suggest you call your hosting company and see what they say.

This was fixed in the update to 5.4.33 on 18 sept. What version of php are you using?

PHP Version 5.4.33 It was updated yesterday and this is when the problems started

The link provided solved the issue