Your submission was sent successfully! Close

You have successfully unsubscribed! Close

Thank you for signing up for our newsletter!
In these regular emails you will find the latest updates about Ubuntu and upcoming events where you can meet our team.Close

USN-3778-1: Firefox vulnerabilities

3 October 2018

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

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.

Learn more about Ubuntu Pro



  • firefox - Mozilla Open Source web browser


A crash was discovered in TransportSecurityInfo used for SSL, which could
be triggered by data stored in the local cache directory. An attacker
could potentially exploit this in combination with another vulnerability
that allowed them to write data to the cache, to execute arbitrary code.

A type confusion bug was discovered in JavaScript. If a user were tricked
in to opening a specially crafted website, an attacker could exploit this
to cause a denial of service, or execute arbitrary code. (CVE-2018-12386)

It was discovered that the Array.prototype.push could leak memory
addresses to the calling function in some circumstances. An attacker could
exploit this in combination with another vulnerability to help execute
arbitrary code. (CVE-2018-12387)

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.

Learn more about Ubuntu Pro

Update instructions

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

Ubuntu 18.04
Ubuntu 16.04
Ubuntu 14.04

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

Related notices

  • USN-3793-1: thunderbird-locale-cs, thunderbird, thunderbird-locale-de, thunderbird-locale-si, thunderbird-locale-et, thunderbird-locale-ko, thunderbird-locale-nl, thunderbird-locale-it, xul-ext-calendar-timezones, thunderbird-locale-ru, thunderbird-locale-sv, thunderbird-locale-hsb, thunderbird-locale-pt-pt, thunderbird-locale-hu, thunderbird-mozsymbols, thunderbird-locale-zh-cn, thunderbird-locale-kk, thunderbird-locale-es-ar, thunderbird-locale-nb-no, thunderbird-locale-sr, xul-ext-gdata-provider, thunderbird-locale-dsb, thunderbird-dev, thunderbird-locale-zh-hant, thunderbird-locale-pt-br, thunderbird-locale-af, thunderbird-locale-bg, thunderbird-locale-bn-bd, thunderbird-locale-is, thunderbird-locale-sq, thunderbird-locale-br, thunderbird-locale-da, thunderbird-locale-fy-nl, thunderbird-locale-zh-hans, thunderbird-locale-he, thunderbird-locale-zh-tw, thunderbird-locale-es, thunderbird-locale-gd, thunderbird-locale-hr, xul-ext-lightning, thunderbird-locale-en-us, thunderbird-locale-fi, thunderbird-locale-nb, thunderbird-locale-be, thunderbird-gnome-support, thunderbird-locale-pa, thunderbird-locale-sl, thunderbird-locale-lt, thunderbird-locale-pl, thunderbird-locale-ro, thunderbird-locale-sk, thunderbird-locale-sv-se, thunderbird-locale-ar, thunderbird-locale-ka, thunderbird-locale-pt, thunderbird-locale-pa-in, thunderbird-locale-nn, thunderbird-locale-ta-lk, thunderbird-locale-el, thunderbird-locale-ga-ie, thunderbird-locale-kab, thunderbird-locale-ta, thunderbird-locale-uk, thunderbird-locale-cy, thunderbird-locale-fr, thunderbird-locale-mk, thunderbird-locale-ast, thunderbird-globalmenu, thunderbird-locale-ca, thunderbird-locale-id, thunderbird-locale-eu, thunderbird-locale-ga, thunderbird-locale-ms, thunderbird-locale-tr, thunderbird-locale-en-gb, thunderbird-testsuite, thunderbird-locale-bn, thunderbird-locale-hy, thunderbird-locale-rm, thunderbird-locale-en, thunderbird-locale-ja, thunderbird-locale-fy, thunderbird-locale-es-es, thunderbird-locale-gl, thunderbird-locale-nn-no, thunderbird-locale-vi