[Rspamd-Users] Need some help with FILENAME_BLACKLISTED

[G.W. Haywood]

Hello again,

On Mon, 5 Sep 2022, G.W. Haywood via Users wrote:

> On Mon, 5 Sep 2022, Andreas Wass - Glas Gasperlmair wrote:
>
>> wanna reject emails wich include filenames with double extensions like 
>> "Testfile.xlsx.txt" an so on.
>> ...
>
> ... In the Windows
> world the extension is something which can have important effects on
> how the operating system behaves, and, for a very long time, naming
> files with deliberately incorrect extensions has been a trick used by
> criminals to compromise victim computers.  In the Unix world, things
> are a bit different: extensions in filenames don't in themselves mean
> anything in particular ...

I neglected to mention that almost always in the Unix world, filenames
are case sensitive.  In the Windows world, they almost always are not.
It's something which may be worth investigating, because the filename
given in a MIME header within the body of a mail message could be given
as "something.exe" or "something.ExE" or "something.eXe" or ... well,
you get the picture.  I'm not even going to mention UTF-8. :)

-- 

73,
Ged.