Dovecot could be made to expose sensitive information over the network.
It was discovered that Dovecot incorrectly validated certificate hostnames when being used as a POP3 and IMAP proxy. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to view sensitive information.
8 December 2011
A security issue affects these releases of Ubuntu and its derivatives:
Dovecot could be made to expose sensitive information over the network.
It was discovered that Dovecot incorrectly validated certificate hostnames when being used as a POP3 and IMAP proxy. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to view sensitive information.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.
Vulmon