USN-3477-4: Firefox regression

3 January 2018

USN-3477-1 caused a regression in Firefox.

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Releases

Packages

  • firefox - Mozilla Open Source web browser

Details

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)

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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.

Learn more about Ubuntu Pro

Update instructions

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

Ubuntu 17.10
Ubuntu 17.04
Ubuntu 16.04
Ubuntu 14.04

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