Is CVE-2021-29946 in the CISA KEV catalog?

No. CVE-2021-29946 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-29946?

CVE-2021-29946 has a CVSS v3 base score of 8.8 (HIGH).

What is the EPSS score for CVE-2021-29946?

CVE-2021-29946 has an EPSS score of 1.17% (64th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-29946?

Upgrade firefox on debian unstable to 88.0-1 or later. Fixes are available for 7 affected products.

CVE & CISA-KEV Catalog

CVE-2021-29946

HIGH

8.8

CVSS v3

NVD

Description

Ports that were written as an integer overflow above the bounds of a 16-bit integer could have bypassed port blocking restrictions when used in the Alt-Svc header. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

CWE-190Integer Overflow

How to fix

Remediation Available

firefoxDebian

Fixed in:88.0-1CVE-2021-29946

firefoxUbuntu

Fixed in:88.0+build2-0ubuntu0.16.04.1USN-4926-1

Fixed in:88.0+build2-0ubuntu0.18.04.2USN-4926-1

Fixed in:88.0+build2-0ubuntu0.20.04.1USN-4926-1

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:88.0Fixed in:88.0Mozilla

Mozilla Firefox (en-US)Windows application

Affected:88.0Fixed in:88.0Mozilla

Mozilla Firefox ESR (en-US)Windows application

Affected:78.10Fixed in:78.10Mozilla

Mozilla Thunderbird (en-US)Windows application

Affected:78.10Fixed in:78.10Mozilla

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

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

1.17%probability of exploitation in 30 days

64thpercentile

Moderate risk: more likely to be exploited than 64% of all known CVEs.

References

Vendor Advisory4

Related Vulnerabilities

Other CWE-190 (Integer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-16040	Medium	6.5	100%	-	Fix
CVE-2019-11477	High	7.5	99%	-	Fix
CVE-2023-44443	High	7.8	94%	-	Fix
CVE-2014-0569	High	9.3	90%	-	-
CVE-2017-3599	High	7.5	90%	-	Fix
CVE-2023-21716	Critical	9.8	82%	-	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.