USN-3477-1: Firefox vulnerabilities

16 November 2017

firefox vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 17.10
  • Ubuntu 17.04
  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS


Firefox could be made to crash or run programs as your login if it opened a malicious website.

Software Description

  • firefox - Mozilla Open Source web browser


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)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 17.10
firefox - 57.0+build4-0ubuntu0.17.10.5
Ubuntu 17.04
firefox - 57.0+build4-0ubuntu0.17.04.5
Ubuntu 16.04 LTS
firefox - 57.0+build4-0ubuntu0.16.04.5
Ubuntu 14.04 LTS
firefox - 57.0+build4-0ubuntu0.14.04.4

To update your system, please follow these instructions:

After a standard system update you need to restart Firefox to make all the necessary changes.