Kerio Connect < 8.1.0 SSL/TLS Information Disclosure (BEAST)
Medium Nessus Plugin ID 72393
Synopsis
The remote mail server is affected by an information disclosure vulnerability.
Description
According to its banner, the remote host is running a version of Kerio Connect (formerly known Kerio MailServer) prior to 8.1.0. It is, therefore, affected by an information disclosure vulnerability, known as BEAST, in the SSL 3.0 and TLS 1.0 protocols due to a flaw in the way the initialization vector (IV) is selected when operating in cipher-block chaining (CBC) modes. A man-in-the-middle attacker can exploit this to obtain plaintext HTTP header data, by using a blockwise chosen-boundary attack (BCBA) on an HTTPS session, in conjunction with JavaScript code that uses the HTML5 WebSocket API, the Java URLConnection API, or the Silverlight WebClient API.
TLS 1.1, TLS 1.2, and all cipher suites that do not use CBC mode are not affected.
Solution
Upgrade to Kerio Connect 8.1.0 or later.