CVE-2021-23984

Description

A malicious extension could have opened a popup window lacking an address bar. The title of the popup lacking an address bar should not be fully controllable, but in this situation was. This could have been used to spoof a website and attempt to trick the user into providing credentials. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.27%
Vendor Advisory mozilla.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org
Affected: Mozilla Firefox ESR
Affected: Mozilla Firefox
Affected: Mozilla Thunderbird
Published at:
Updated at:

References

Link Tags
https://www.mozilla.org/security/advisories/mfsa2021-10/ vendor advisory
https://www.mozilla.org/security/advisories/mfsa2021-12/ vendor advisory
https://www.mozilla.org/security/advisories/mfsa2021-11/ vendor advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1693664 vendor advisory issue tracking

Frequently Asked Questions

What is the severity of CVE-2021-23984?
CVE-2021-23984 has been scored as a medium severity vulnerability.
How to fix CVE-2021-23984?
To fix CVE-2021-23984, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-23984 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-23984 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-23984?
CVE-2021-23984 affects Mozilla Firefox ESR, Mozilla Firefox, Mozilla Thunderbird.
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