10 - USN-2673-1

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 15.04 - Ubuntu 14.10 - Ubuntu 14.04 LTS - Ubuntu 12.04 LTS

Summary:

Several security issues were fixed in Thunderbird.

Software Description: - thunderbird: Mozilla Open Source mail and newsgroup client

Details:

Karthikeyan Bhargavan discovered that NSS incorrectly handled state transitions for the TLS state machine. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to skip the ServerKeyExchange message and remove the forward-secrecy property. (CVE-2015-2721)

Bob Clary, Christian Holler, Bobby Holley, and Andrew McCreight discovered multiple memory safety issues in Thunderbird. If a user were tricked in to opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service via application crash, or execute arbitrary code with the privileges of the user invoking Thunderbird. (CVE-2015-2724)

Ronald Crane discovered multiple security vulnerabilities. If a user were tricked in to opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service via application crash, or execute arbitrary code with the privileges of the user invoking Thunderbird. (CVE-2015-2734, CVE-2015-2735, CVE-2015-2736, CVE-2015-2737, CVE-2015-2738, CVE-2015-2739, CVE-2015-2740)

Matthew Green discovered a DHE key processing issue in NSS where a MITM could force a server to downgrade TLS connections to 512-bit export-grade cryptography. An attacker could potentially exploit this to impersonate the server. (CVE-2015-4000)

Update instructions:

The problem can be corrected by updating your system to the following package versions:

Ubuntu 15.04:
thunderbird 1:31.8.0+build1-0ubuntu0.15.04.1

Ubuntu 14.10:
thunderbird 1:31.8.0+build1-0ubuntu0.14.10.1

Ubuntu 14.04 LTS:
thunderbird 1:31.8.0+build1-0ubuntu0.14.04.1

Ubuntu 12.04 LTS:
thunderbird 1:31.8.0+build1-0ubuntu0.12.04.1

After a standard system update you need to restart Thunderbird to make all the necessary changes.

References:
http://www.ubuntu.com/usn/usn-2673-1
CVE-2015-2721, CVE-2015-2724, CVE-2015-2734, CVE-2015-2735,
CVE-2015-2736, CVE-2015-2737, CVE-2015-2738, CVE-2015-2739,
CVE-2015-2740, CVE-2015-4000

Package Information:
https://launchpad.net/ubuntu/+source/thunderbird/1:31.8.0+build1-0ubuntu0.15.04.1
https://launchpad.net/ubuntu/+source/thunderbird/1:31.8.0+build1-0ubuntu0.14.10.1
https://launchpad.net/ubuntu/+source/thunderbird/1:31.8.0+build1-0ubuntu0.14.04.1
https://launchpad.net/ubuntu/+source/thunderbird/1:31.8.0+build1-0ubuntu0.12.04.1