Firefox could be made to crash or run programs as your login if it opened a malicious website.
A sandbox escape was discovered in Firefox. If a user were tricked in to installing a malicious language pack, an attacker could exploit this to gain additional privileges. (CVE-2019-9811)
12 July 2019
A security issue affects these releases of Ubuntu and its derivatives:
Firefox could be made to crash or run programs as your login if it opened a malicious website.
A sandbox escape was discovered in Firefox. If a user were tricked in to installing a malicious language pack, an attacker could exploit this to gain additional privileges. (CVE-2019-9811)
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, obtain sensitive information, bypass same origin restrictions, conduct cross-site scripting (XSS) attacks, conduct cross-site request forgery (CSRF) attacks, spoof origin attributes, spoof the addressbar contents, bypass safebrowsing protections, or execute arbitrary code. (CVE-2019-11709, CVE-2019-11710, CVE-2019-11711, CVE-2019-11712, CVE-2019-11713, CVE-2019-11714, CVE-2019-11715, CVE-2019-11716, CVE-2019-11717, CVE-2019-11718, CVE-2019-11719, CVE-2019-11720, CVE-2019-11721, CVE-2019-11723, CVE-2019-11724, CVE-2019-11725, CVE-2019-11727, CVE-2019-11728, CVE-2019-11729)
It was discovered that Firefox treats all files in a directory as same origin. If a user were tricked in to downloading a specially crafted HTML file, an attacker could potentially exploit this to obtain sensitive information from local files. (CVE-2019-11730)
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.