Is CVE-2021-24042 in the CISA KEV catalog?

No. CVE-2021-24042 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-24042?

CVE-2021-24042 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2021-24042?

CVE-2021-24042 has an EPSS score of 1.24% (66th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-24042?

Upgrade whatsapp to 2.21.23 or later.

CVE & CISA-KEV Catalog

CVE-2021-24042

CRITICAL

9.8

CVSS v3

NVD

Description

The calling logic for WhatsApp for Android prior to v2.21.23, WhatsApp Business for Android prior to v2.21.23, WhatsApp for iOS prior to v2.21.230, WhatsApp Business for iOS prior to v2.21.230, WhatsApp for KaiOS prior to v2.2143, WhatsApp Desktop prior to v2.2146 could have allowed an out-of-bounds write if a user makes a 1:1 call to a malicious actor.

CWE-122Heap-based Buffer Overflow CWE-787Out-of-bounds Write

How to fix

Remediation Available

whatsappNVD

Affected:< 2.21.23Fixed in:2.21.23CVE-2021-24042derived from NVD

Affected:< 2.21.230Fixed in:2.21.230CVE-2021-24042derived from NVD

Affected:< 2.2143Fixed in:2.2143CVE-2021-24042derived from NVD

Affected:< 2.2146Fixed in:2.2146CVE-2021-24042derived 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

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

1.24%probability of exploitation in 30 days

66thpercentile

Moderate risk: more likely to be exploited than 66% of all known CVEs.

References

Vendor Advisory1

whatsapp.com

Related Vulnerabilities

Other CWE-122 (Heap-based Buffer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2015-3113	Critical	9.8	100%	KEV	Fix
CVE-2024-26256	High	7.8	88%	-	Fix
CVE-2020-25687	Medium	5.9	87%	-	Fix
CVE-2009-3459	High	8.8	86%	KEV	Fix
CVE-2021-21017	High	8.8	86%	KEV	-
CVE-2020-25683	Medium	5.9	86%	-	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 2025-05-22.