firefox vulnerabilities

A use-after-free was discovered when resizing a canvas element during
restyling 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-2015-4497)

Bas Venis discovered that the addon install permission prompt could be
bypassed using data: URLs in some circumstances. It was also discovered
that the installation notification could be made to appear over another
site. If a user were tricked in to opening a specially crafted website, an
attacker could potentially exploit this to install a malicious addon.
(CVE-2015-4498)