USN-3216-2: Firefox regression

Ubuntu Security Notice USN-3216-2

30th March, 2017

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

USN-3216-1 introduced a regression in Firefox.

USN-3216-1 fixed vulnerabilities in Firefox. The update resulted in a
startup crash when Firefox is used with XRDP. This update fixes the
problem.

We apologize for the inconvenience.

Original advisory details:

Multiple security issues were discovered in Firefox. If a user were
tricked in to opening a specially crafted website, an attacker could
potentially exploit these to bypass same origin restrictions, obtain
sensitive information, spoof the addressbar, spoof the print dialog,
cause a denial of service via application crash or hang, or execute
arbitrary code. (CVE-2017-5398, CVE-2017-5399, CVE-2017-5400,
CVE-2017-5401, CVE-2017-5402, CVE-2017-5403, CVE-2017-5404, CVE-2017-5405,
CVE-2017-5406, CVE-2017-5407, CVE-2017-5408, CVE-2017-5410, CVE-2017-5412,
CVE-2017-5413, CVE-2017-5414, CVE-2017-5415, CVE-2017-5416, CVE-2017-5417,
CVE-2017-5418, CVE-2017-5419, CVE-2017-5420, CVE-2017-5421, CVE-2017-5422,
CVE-2017-5426, CVE-2017-5427)

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

To update your system, please follow these instructions:
https://wiki.ubuntu.com/Security/Upgrades.

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