Ubuntu: USN-2880-2: Firefox regression

Description

USN-2880-1 fixed vulnerabilities in Firefox. This update introduced a regression which caused Firefox to crash on startup with some configurations. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

Bob Clary, Christian Holler, Nils Ohlmeier, Gary Kwong, Jesse Ruderman, Carsten Book, Randell Jesup, Nicolas Pierron, Eric Rescorla, Tyson Smith, and Gabor Krizsanits discovered multiple memory safety issues in Firefox. If a user were tricked in to opening a specially crafted website, 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 Firefox. (CVE-2016-1930,CVE-2016-1931) Gustavo Grieco discovered an out-of-memory crash when loading GIF images in some circumstances. If a user were tricked in to opening a specially crafted website, an attacker could exploit this to cause a denial of service. (CVE-2016-1933) Aki Helin discovered a buffer overflow when rendering WebGL content in some circumstances. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit this to cause a denial of service via application crash, or execute arbitrary code with the privileges of the user invoking Firefox. (CVE-2016-1935) It was discovered that a delay was missing when focusing the protocol handler dialog. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit this to conduct clickjacking attacks. (CVE-2016-1937) Hanno Böck discovered that calculations with mp_div and mp_exptmod in NSS produce incorrect results in some circumstances, resulting in cryptographic weaknesses. (CVE-2016-1938) Nicholas Hurley discovered that Firefox allows for control characters to be set in cookie names. An attacker could potentially exploit this to conduct cookie injection attacks on some web servers. (CVE-2016-1939) It was discovered that when certain invalid URLs are pasted in to the addressbar, the addressbar contents may be manipulated to show the location of arbitrary websites. An attacker could potentially exploit this to conduct URL spoofing attacks. (CVE-2016-1942) Ronald Crane discovered three vulnerabilities through code inspection. If a user were tricked in to opening a specially crafted website, 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 Firefox. (CVE-2016-1944,CVE-2016-1945,CVE-2016-1946) François Marier discovered that Application Reputation lookups didn't work correctly, disabling warnings for potentially malicious downloads. An attacker could potentially exploit this by tricking a user in to downloading a malicious file. Other parts of the Safe Browsing feature were unaffected by this. (CVE-2016-1947)