firefox-esr - security update

A use-after-free vulnerability in the SVG Animation was discovered in
the Mozilla Firefox web browser, allowing a remote attacker to cause a
denial of service (application crash) or execute arbitrary code, if a
user is tricked into opening a specially crafted website.

For the stable distribution (jessie), this problem has been fixed in
version 45.5.1esr-1~deb8u1.

We recommend that you upgrade your firefox-esr packages.