Software Engineering Institute

According to Barracuda Networks, the Barracuda Web Filter is a "comprehensive solution for web security and management" with many features, including the ability to provide "visibility into SSL-encrypted traffic". This SSL inspection feature of the Barracuda Web Filter is vulnerable to multiple issues.

Incomplete validation of upstream certificate validity - CVE-2015-0961

Barracuda Web Filter versions between 7.0 and 8.1.0.005 do not check upstream certificate validity when performing SSL inspection.

Shared root CA certificate - CVE-2015-0962

Barracuda Web Filter versions between 7.0 and 8.1.0.005 ship one of three different default certificates that are shared across multiple machine for use in the SSL Inspection feature.

The impact of either CVE-2015-0961 or CVE-2015-0962 may allow an attacker to successfully achieve a man-in-the-middle (MITM) attack without the client knowing it.

Update the firmware

Barracuda Networks has released firmware version 8.1.0.005 on April 16th, 2015 to address these issues. Affected users should upgrade to firmware 8.1.0.005 or later as soon as possible.

Users who have deployed an affected service using the default certificate supplied with the appliance will need to deploy a new client certificate to their clients and remove the previously deployed certificate. Instructions for deploying and removing client certificates are available at http://techlib.barracuda.com/BWF/UpdateSSLCerts.

Check that old shared certificates are removed

Barracuda has also provided https://certcheck.barracudalabs.com, a site that will show users if their browser trusts any of the shared default certificates and includes instructions for removing the certificates from the browser trust store if necessary.