CVE-2021-38506

Medium

Description

Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

SeverityMedium

CVSS4.3

Exploit probability—

Product

Mozilla Firefox

PublishedDec 8, 2021

First seenDec 8, 2021

How to fix

Update

mozilla firefox94.0 or later
mozilla firefox_esr91.3.0 or later
mozilla thunderbird91.3.0 or later

Vendor advisories

debian.org/security/2021/dsa-5026
debian.org/security/2022/dsa-5034
security.gentoo.org/glsa/202202-03
security.gentoo.org/glsa/202208-14

Affected products

Product	Affected versions	Fixed in
mozilla firefox	v < 94.0	94.0
mozilla firefox_esr	v < 91.3.0	91.3.0
mozilla thunderbird	v < 91.3.0	91.3.0
debian debian_linux	9.0, 10.0, 11.0	—

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.