USN-3477-1 caused a regression in Firefox.
USN-3477-1 fixed vulnerabilities in Firefox. The update introduced a crash reporting issue where background tab crash reports were sent to Mozilla without user opt-in. This update fixes the problem.
3 January 2018
A security issue affects these releases of Ubuntu and its derivatives:
USN-3477-1 caused a regression in Firefox.
USN-3477-1 fixed vulnerabilities in Firefox. The update introduced a crash reporting issue where background tab crash reports were sent to Mozilla without user opt-in. 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 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)
The problem can be corrected by updating your system to the following package versions:
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.
Vulmon