USN-3596-2: Firefox regression

06 April 2018

USN-3596-1 caused a regression in Firefox.

Releases

Packages

  • firefox - Mozilla Open Source web browser

Details

USN-3596-1 fixed vulnerabilities in Firefox. The update caused an issue
where it was not possible to customize the toolbars when running Firefox
in Unity. 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 via application
crash or opening new tabs, escape the sandbox, bypass same-origin
restrictions, obtain sensitive information, confuse the user with
misleading permission requests, or execute arbitrary code. (CVE-2018-5125,
CVE-2018-5126, CVE-2018-5127, CVE-2018-5128, CVE-2018-5129, CVE-2018-5130,
CVE-2018-5136, CVE-2018-5137, CVE-2018-5140, CVE-2018-5141, CVE-2018-5142)

It was discovered that the fetch() API could incorrectly return cached
copies of no-store/no-cache resources in some circumstances. A local
attacker could potentially exploit this to obtain sensitive information in
environments where multiple users share a common profile. (CVE-2018-5131)

Multiple security issues were discovered with WebExtensions. If a user
were tricked in to installing a specially crafted extension, an attacker
could potentially exploit these to obtain sensitive information or bypass
security restrictions. (CVE-2018-5132, CVE-2018-5134, CVE-2018-5135)

It was discovered that the value of app.support.baseURL is not sanitized
properly. If a malicious local application were to set this to a specially
crafted value, an attacker could potentially exploit this to execute
arbitrary code. (CVE-2018-5133)

It was discovered that javascript: URLs with embedded tab characters could
be pasted in to the addressbar. If a user were tricked in to copying a
specially crafted URL in to the addressbar, an attacker could exploit this
to conduct cross-site scripting (XSS) attacks. (CVE-2018-5143)

Update instructions

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

Ubuntu 16.04
Ubuntu 14.04

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