14 DAY TRIAL // On August 18, Canonical announced the immediate availability of new kernel updates for its supported Ubuntu Linux operating systems, including Ubuntu 15.04 (Vivid Vervet), Ubuntu 14.04 LTS (Trusty Tahr), and Ubuntu 12.04 LTS (Precise Pangolin).
Today's updates patch three security flaws in the Linux kernel packages of Ubuntu 12.04 LTS, and one kernel vulnerability on the Ubuntu 15.04 and Ubuntu 14.04 LTS operating systems.
The common kernel vulnerability to all three Ubuntu distributions is a race condition discovered by Marcelo Ricardo Leitner in Linux kernel's Stream Control Transmission Protocol (SCTP) address configuration lists.
The security flaw was discovered when using the ASCONF (Address Configuration Change) options on a socket and could allow a local user that had no root privileges to crash the target system by causing a denial of service.
As mentioned, two other security flaws have been patched in Ubuntu 12.04 LTS, both discovered in Linux kernel's handling of invalid User Datagram Protocol (UDP) checksums, which could lead to denial of service attacks.
All Ubuntu users must update as soon as possible
Canonical urges all users of the Ubuntu 15.04, Ubuntu 14.04 LTS, and Ubuntu 12.04 LTS operating systems to update their systems as soon as possible via the official channels. To update, simply fire up the Software Updater utility and apply all existing updates.
Please note that you will need to restart your system after a kernel update for it to be applied correctly, as well as to manually reinstall any third-party modules that you might have.
After the update, make sure that your kernel packages match linux-image-3.2.0-89 (3.2.0-89.127) on Ubuntu 12.04 LTS, linux-image-3.13.0-62 (3.13.0-62.102) on Ubuntu 14.04 LTS, and linux-image-3.19.0-26 (3.19.0-26.28) on Ubuntu 15.04.