Affected: Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird

A use-after-free vulnerability can occur when flushing and resizing layout because the "PressShell" object has been freed while still in use. This results in a potentially exploitable crash during these operations. This vulnerability affects Firefox < 57, Firefox ESR < 52.5, and Thunderbird < 52.5.

Affected: Ubuntu:14.04:LTS: firefox, Ubuntu:16.04:LTS: firefox

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 cause a denial of service, read uninitialized memory, obtain sensitive information, bypass same-origin restrictions, bypass CSP protections, bypass mixed content blocking, spoof the addressbar, or execute arbitrary code. (CVE-2017-7826, CVE-2017-7827, CVE-2017-7828, CVE-2017-7830, CVE-2017-7831, CVE-2017-7832, CVE-2017-7833, CVE-2017-7834, CVE-2017-7835, CVE-2017-7837, CVE-2017-7838, CVE-2017-7842)

It was discovered that javascript: URLs pasted in to the addressbar would be executed instead of being blocked in some circumstances. If a user were tricked in to copying a specially crafted URL in to the addressbar, an attacker could potentially exploit this to conduct cross-site scripting (XSS) attacks. (CVE-2017-7839)

It was discovered that exported bookmarks do not strip script elements from user-supplied tags. If a user were tricked in to adding specially crafted tags to bookmarks, exporting them and then opening the resulting HTML file, an attacker could potentially exploit this to conduct cross-site scripting (XSS) attacks. (CVE-2017-7840)