Your submission was sent successfully! Close

You have successfully unsubscribed! Close

USN-4926-1: Firefox vulnerabilities

26 April 2021

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

Releases

Packages

  • firefox - Mozilla Open Source web browser

Details

Multiple security issues were discovered in Firefox. If a user were
tricked into opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, spoof the
browser UI, bypass security restrictions, trick the user into disclosing
confidential information, or execute arbitrary code. (CVE-2021-23994,
CVE-2021-23996, CVE-2021-23997, CVE-2021-23998, CVE-2021-23999,
CVE-2021-24000, CVE-2021-24001, CVE-2021-29945, CVE-2021-29946,
CVE-2021-29947)

A use-after-free was discovered when Responsive Design Mode was
enabled. If a user were tricked into opening a specially crafted
website with Responsive Design Mode enabled, an attacker could
potentially exploit this to cause a denial of service, or execute
arbitrary code. (CVE-2021-23995)

It was discovered that Firefox mishandled ftp URLs with encoded newline
characters. If a user were tricked into clicking on a specially crafted
link, an attacker could potentially exploit this to send arbitrary
FTP commands. (CVE-2021-24002)

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 21.04
Ubuntu 20.10
Ubuntu 20.04
Ubuntu 18.04
Ubuntu 16.04

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

Related notices

  • USN-4995-1: thunderbird-locale-ms, thunderbird-locale-lt, thunderbird-locale-sv, thunderbird-locale-be, thunderbird-locale-dsb, thunderbird-locale-gl, thunderbird-locale-ta-lk, thunderbird-locale-it, thunderbird-locale-zh-hans, xul-ext-lightning, thunderbird-locale-ta, thunderbird-locale-ro, thunderbird-locale-vi, thunderbird-locale-sk, thunderbird-locale-cak, thunderbird-locale-bg, thunderbird-locale-fy, xul-ext-calendar-timezones, thunderbird-locale-es-ar, thunderbird-locale-pt-br, thunderbird-locale-en-gb, thunderbird-locale-fi, thunderbird-locale-es, thunderbird-locale-uz, thunderbird, thunderbird-locale-bn, thunderbird-locale-fr, thunderbird-locale-nl, thunderbird-locale-pl, thunderbird-locale-zh-cn, thunderbird-locale-hu, thunderbird-locale-si, thunderbird-locale-sv-se, thunderbird-locale-kab, thunderbird-dev, thunderbird-locale-nb, thunderbird-locale-ar, thunderbird-locale-fy-nl, thunderbird-locale-ca, thunderbird-locale-en, thunderbird-locale-kk, thunderbird-locale-br, thunderbird-locale-cy, thunderbird-locale-et, thunderbird-locale-gd, thunderbird-locale-ja, thunderbird-locale-hr, thunderbird-locale-ga, thunderbird-locale-ast, thunderbird-locale-pt, thunderbird-locale-is, thunderbird-locale-ka, thunderbird-locale-cs, thunderbird-locale-tr, thunderbird-locale-nn-no, thunderbird-locale-hy, thunderbird-locale-pa-in, thunderbird-locale-sq, thunderbird-mozsymbols, thunderbird-locale-nn, thunderbird-locale-ru, thunderbird-locale-es-es, thunderbird-locale-th, thunderbird-locale-sl, thunderbird-locale-id, thunderbird-gnome-support, thunderbird-locale-rm, thunderbird-locale-uk, thunderbird-locale-pa, thunderbird-locale-zh-tw, thunderbird-locale-el, thunderbird-locale-ga-ie, thunderbird-locale-he, thunderbird-locale-eu, thunderbird-locale-bn-bd, thunderbird-locale-af, thunderbird-locale-da, thunderbird-locale-nb-no, xul-ext-gdata-provider, thunderbird-locale-zh-hant, thunderbird-locale-de, thunderbird-locale-en-us, thunderbird-locale-pt-pt, thunderbird-locale-hsb, thunderbird-locale-mk, thunderbird-locale-ko, thunderbird-locale-fa, thunderbird-locale-sr
  • USN-4995-2: thunderbird-locale-ms, thunderbird-locale-lt, thunderbird-locale-sv, thunderbird-locale-be, thunderbird-locale-dsb, thunderbird-locale-gl, thunderbird-locale-ta-lk, thunderbird-locale-it, thunderbird-locale-zh-hans, xul-ext-lightning, thunderbird-locale-ta, thunderbird-locale-ro, thunderbird-locale-vi, thunderbird-locale-sk, thunderbird-locale-cak, thunderbird-locale-bg, thunderbird-locale-fy, xul-ext-calendar-timezones, thunderbird-locale-es-ar, thunderbird-locale-pt-br, thunderbird-locale-en-gb, thunderbird-locale-fi, thunderbird-locale-es, thunderbird-locale-uz, thunderbird, thunderbird-locale-bn, thunderbird-locale-fr, thunderbird-locale-nl, thunderbird-locale-pl, thunderbird-locale-zh-cn, thunderbird-locale-hu, thunderbird-locale-si, thunderbird-locale-sv-se, thunderbird-locale-kab, thunderbird-dev, thunderbird-locale-nb, thunderbird-locale-ar, thunderbird-locale-fy-nl, thunderbird-locale-ca, thunderbird-locale-en, thunderbird-locale-kk, thunderbird-locale-br, thunderbird-locale-cy, thunderbird-locale-et, thunderbird-locale-gd, thunderbird-locale-ja, thunderbird-locale-hr, thunderbird-locale-ga, thunderbird-locale-ast, thunderbird-locale-pt, thunderbird-locale-is, thunderbird-locale-ka, thunderbird-locale-cs, thunderbird-locale-tr, thunderbird-locale-nn-no, thunderbird-locale-hy, thunderbird-locale-pa-in, thunderbird-locale-sq, thunderbird-mozsymbols, thunderbird-locale-nn, thunderbird-locale-ru, thunderbird-locale-es-es, thunderbird-locale-th, thunderbird-locale-sl, thunderbird-locale-id, thunderbird-gnome-support, thunderbird-locale-rm, thunderbird-locale-uk, thunderbird-locale-pa, thunderbird-locale-zh-tw, thunderbird-locale-el, thunderbird-locale-ga-ie, thunderbird-locale-he, thunderbird-locale-eu, thunderbird-locale-bn-bd, thunderbird-locale-af, thunderbird-locale-da, thunderbird-locale-nb-no, xul-ext-gdata-provider, thunderbird-locale-zh-hant, thunderbird-locale-de, thunderbird-locale-en-us, thunderbird-locale-pt-pt, thunderbird-locale-hsb, thunderbird-locale-mk, thunderbird-locale-ko, thunderbird-locale-fa, thunderbird-locale-sr