Is CVE-2021-43824 in the CISA KEV catalog?

No. CVE-2021-43824 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-43824?

CVE-2021-43824 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2021-43824?

CVE-2021-43824 has an EPSS score of 1.05% (60th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-43824?

Upgrade envoy to 1.21.1 or later.

CVE & CISA-KEV Catalog

CVE-2021-43824

HIGH

7.5

CVSS v3

NVD

Description

Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions a crafted request crashes Envoy when a CONNECT request is sent to JWT filter configured with regex match. This provides a denial of service attack vector. The only workaround is to not use regex in the JWT filter. Users are advised to upgrade.

CWE-476NULL Pointer Dereference

How to fix

Remediation Available

envoyNVD

Affected:>= 1.21.0, < 1.21.1Fixed in:1.21.1CVE-2021-43824derived from NVD

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 InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

1.05%probability of exploitation in 30 days

60thpercentile

Moderate risk: more likely to be exploited than 60% of all known CVEs.

References

Patch1

github.com

Third-Party Advisory1

github.com

Related Vulnerabilities

Other CWE-476 (NULL Pointer Dereference) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-21758	High	7.5	92%	-	Fix
CVE-2023-21547	High	7.5	88%	-	Fix
CVE-2014-3470	Medium	4.3	86%	-	Fix
CVE-2021-44224	High	8.2	82%	-	Fix
CVE-2016-0742	High	7.5	82%	-	Fix
CVE-2009-1386	Medium	5.0	80%	-	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.