How severe is CVE-2021-24042?

CVE-2021-24042 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-24042 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-24042?

CVE-2021-24042 primarily affects Whatsapp. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-24042?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-24042 published?

CVE-2021-24042 was published on 2022-01-04 and last updated on 2026-06-17.

CVE-2021-24042

CVE-2021-24042 is a critical-severity vulnerability in Whatsapp with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (66th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Whatsapp
Published: 2022-01-04
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-24042?: 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.
How severe is CVE-2021-24042?: CVE-2021-24042 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-24042 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-24042?: CVE-2021-24042 primarily affects Whatsapp. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-24042?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-24042 published?: CVE-2021-24042 was published on 2022-01-04 and last updated on 2026-06-17.

References

https://www.whatsapp.com/security/advisories/2021/

Affected products (6)

cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:*:android:-:*
cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:business:android:*:*
cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:*:iphone_os:-:*
cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:business:iphone_os:-:*
cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:*:kaios:*:*
cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:desktop:-:*:*

More vulnerabilities in Whatsapp

CVE-2022-36934 — Critical (CVSS 9.8): An integer overflow in WhatsApp could result in remote code execution in an established video call.
CVE-2021-24041 — Critical (CVSS 9.8): A missing bounds check in image blurring code prior to WhatsApp for Android v2.21.22.7 and WhatsApp Business for…
CVE-2021-24026 — Critical (CVSS 9.8): A missing bounds check within the audio decoding pipeline for WhatsApp calls in WhatsApp for Android prior to v2.21.3,…
CVE-2020-1909 — Critical (CVSS 9.8): A use-after-free in a logging library in WhatsApp for iOS prior to v2.20.111 and WhatsApp Business for iOS prior to…
CVE-2020-1907 — Critical (CVSS 9.8): A stack overflow in WhatsApp for Android prior to v2.20.196.16, WhatsApp Business for Android prior to v2.20.196.12,…
CVE-2020-1891 — Critical (CVSS 9.8): A user controlled parameter used in video call in WhatsApp for Android prior to v2.20.17, WhatsApp Business for Android…

All CVEs affecting Whatsapp →

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