--- title: 'USN-3435-2: Firefox regression | Ubuntu security notices' description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/notices/USN-3435-2 --- 1. [Ubuntu Security Notices](https://ubuntu.com/security/notices) 2. USN-3435-2 --- # USN-3435-2: Firefox regression Publication date 4 October 2017 Overview USN-3435-1 caused a regression in Firefox. Releases [17.04](https://ubuntu.com/security/notices?release=zesty) [16.04 LTS](https://ubuntu.com/security/notices?release=xenial) [14.04 LTS](https://ubuntu.com/security/notices?release=trusty) --- Open side navigation ## Packages * [firefox](https://ubuntu.com/security/cves?package=firefox) - Mozilla Open Source web browser ## Details USN-3435-1 fixed vulnerabilities in Firefox. The update caused the Flash plugin to crash in some circumstances. 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 read uninitialized memory, obtain sensitive information, bypass phishing and malware protection, spoof the origin in modal dialogs, conduct cross-site scripting (XSS) attacks, cause a denial of service via application crash, or execute arbitrary code. ([CVE-2017-7793](https://ubuntu.com/security/CVE-2017-7793), [CVE-2017-7810](https://ubuntu.com/security/CVE-2017-7810), [CVE-2017-7811](https://ubuntu.com/security/CVE-2017-7811), [CVE-2017-7812](https://ubuntu.com/security/CVE-2017-7812), [CVE-2017-7813](https://ubuntu.com/security/CVE-2017-7813), --- Show more ## Update instructions After a standard system update you need to restart Firefox to make all the necessary changes. [Learn more about how to get the fixes.](https://ubuntu.com/security/cves/about#security) The problem can be corrected by updating your system to the following package versions: | Ubuntu Release | Package Version | | --- | --- | | 17.04 zesty | [firefox](https://launchpad.net/ubuntu/+source/firefox) –  [56.0+build6-0ubuntu0.17.04.2](https://launchpad.net/ubuntu/+source/firefox/56.0+build6-0ubuntu0.17.04.2) | | | | 16.04 LTS xenial | [firefox](https://launchpad.net/ubuntu/+source/firefox) –  [56.0+build6-0ubuntu0.16.04.2](https://launchpad.net/ubuntu/+source/firefox/56.0+build6-0ubuntu0.16.04.2) | | | | 14.04 LTS trusty | [firefox](https://launchpad.net/ubuntu/+source/firefox) –  [56.0+build6-0ubuntu0.14.04.2](https://launchpad.net/ubuntu/+source/firefox/56.0+build6-0ubuntu0.14.04.2) | | | --- ### Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. [Get Ubuntu Pro](https://ubuntu.com/pro) ## References *