14 DAY TRIAL // Several security updates for Ubuntu 11.10, Ubuntu 11.04, Ubuntu 10.10, and Ubuntu 10.04 LTS have been released by Canonical.
The first fix relates to Dovecot which could have been made to expose sensitive information over the network because it incorrectly validated certificate hostnames when being used as a IMAP and POP3 proxy.
The second exploit was discovered by Oliver-Tobias Ripka. The power button events were incorrectly handled by the ACPI script, therefore a local attacker could use it to execute arbitrary code and escalate privileges.
The third and final security update is for python-django web development framework, because apps using Django could be made to crash or expose sensitive information.
To plug all these problems just run the following commands, in a terminal, or run the integrated updater:
sudo apt-get update sudo apt-get dist-upgrade