Martijn,
Thanks for the reminder, I did indeed already configure the previous
certificate manually in now reconfigured postfix to use the new one.
I also made many changes to the protocols and ciphers used by the smtp deamon
and client, so only Tls1.2 with strong ciphers is available now.
(our Ciphermail is 'inbetween' smtp server in our own network, so no
unpredicted fallback to *no* TLS would occur, but it is also unavailable now).
One last item from the Security Scan remains: a vulnerable version of JQuery
seems to be installed in the appliance VM.
The remote web server is affected by multiple cross site scripting
vulnerability.
Description
According to the self-reported version in the script, the version of
JQuery hosted on the remote web server is greater than or equal to 1.2 and
prior to 3.5.0.
It is, therefore, affected by multiple cross site scripting
vulnerabilities.
Can this be fixed?
Met vriendelijke groet / Regards,
Michel Erdmann
-----Original Message-----
From: Martijn Brinkers <[email protected]>
Sent: dinsdag 25 mei 2021 16:27
To: [email protected]
Cc: Erdmann, M. (LISA) <[email protected]>
Subject: Re: [CipherMail User] Security scans, changes needed
> I’ve replaced the web GUI certificate (done that many times), but the
> old certificate appears still to be in use for SMTP. This certificate
> is now expired.
> How can the MTA be configured to use the new certificate?
The community edition of the virtual appliance does not support uploading a new
cert for the MTA (the pro/enterprise edition has support for this). So you, or
someone else, probably uploaded and configured the cert manually. Since the
underlying SMTP is postfix, it should be easy to replace the certificate.
Note: in the upcoming release of the community edition we also copy the cert
for the web GUI to the postfix config.
> I’m using an appliance VM image (V4.3.0-1, with the latest updates),
> and it is still using TLS1.0/1.1, SSLv3 and RC4 cipher suites How can
> those old protocols/ciphers be disabled?
It should be noted that Postfix (and SMTP in general) by default provides
opportunistic TLS, i.e., use TLS if available, if not connect with TLS.
Disabling weak ciphers does not increase the security level if you still allow
unencrypted connections (when DANE is used things are different). That said,
since Postfix is used for the MTA part, you can easily disable weak ciphers.
For example to disable TLS <= 1.1 add the following line to te postfix main
config (main.cf)
smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1
The above configuration disables TLS <= 1.1 for the SMTP daemon
If you would like to disable weak ciphermail for the SMTP client, use
smtp_tls_mandatory_protocols
Again, disabling weak ciphers might result in fallback to *no* TLS if the SMTP
server you are connecting to does not support TLS >= 1.2
For more information on TLS configuration of Postfix see:
http://www.postfix.org/TLS_README.html
For the upcoming release of the gateway we will review the default TLS
configuration.
Kind regards,
Martijn Brinkers
--
CipherMail email encryption
Email encryption with support for S/MIME, OpenPGP, PDF Messenger and Webmail
Messenger
On Tue, 2021-05-25 at 13:35 +0000, m.erdmann--- via Users wrote:
> Hello,
>
> Our security department scanned the ciphermail gateway and is seeing
> issues that need to be fixed:
>
> I’ve replaced the web GUI certificate (done that many times), but the
> old certificate appears still to be in use for SMTP. This certificate
> is now expired.
> How can the MTA be configured to use the new certificate?
> I’m using an appliance VM image (V4.3.0-1, with the latest updates),
> and it is still using TLS1.0/1.1, SSLv3 and RC4 cipher suites How can
> those old protocols/ciphers be disabled?
>
> More issues are found, but I’ll focus on these issues first.
>
> Met vriendelijke groet / Regards,
>
> Michel Erdmann
>
