Is CVE-2021-23984 in the CISA KEV catalog?

No. CVE-2021-23984 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-23984?

CVE-2021-23984 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2021-23984?

CVE-2021-23984 has an EPSS score of 1.11% (62th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-23984?

Upgrade firefox on debian unstable to 87.0-1 or later. Fixes are available for 7 affected products.

CVE & CISA-KEV Catalog

CVE-2021-23984

MEDIUM

6.5

CVSS v3

NVD

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.

CWE-290

How to fix

Remediation Available

firefoxDebian

Fixed in:87.0-1CVE-2021-23984

firefoxUbuntu

Fixed in:87.0+build3-0ubuntu0.16.04.2USN-4893-1

Fixed in:87.0+build3-0ubuntu0.18.04.2USN-4893-1

Fixed in:87.0+build3-0ubuntu0.20.04.2USN-4893-1

thunderbirdUbuntu

Fixed in:1:78.11.0+build1-0ubuntu0.18.04.2USN-4995-2

Fixed in:1:78.11.0+build1-0ubuntu0.20.04.2USN-4995-1

DeveloperEditionWindows application

Affected:87.0Fixed in:87.0Mozilla

Mozilla Firefox (en-US)Windows application

Affected:87.0Fixed in:87.0Mozilla

Mozilla Firefox ESR (en-US)Windows application

Affected:78.9Fixed in:78.9Mozilla

Mozilla Thunderbird (en-US)Windows application

Affected:78.9Fixed in:78.9Mozilla

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Exploit Intelligence

1.11%probability of exploitation in 30 days

62ndpercentile

Moderate risk: more likely to be exploited than 62% of all known CVEs.

References

Vendor Advisory4

Related Vulnerabilities

Other CWE-290 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-4358	Critical	9.8	97%	KEV	-
CVE-2022-24112	Critical	9.8	96%	KEV	Fix
CVE-2022-23131	Critical	9.1	96%	KEV	-
CVE-2021-29441	High	8.6	74%	-	Fix
CVE-2021-31195	Medium	6.5	74%	-	Fix
CVE-2020-7388	Critical	10.0	70%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.