# Heap-based buffer overflow in Facebook WhatsApp Desktop and others

CVE record · `CVE-2021-24042`

- **Identifiers:** `CVE-2021-24042`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **CNA:** facebook
- **Weakness (CWE):** [CWE-122](https://cwe.mitre.org/data/definitions/122.html) · [CWE-787](https://cwe.mitre.org/data/definitions/787.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md)
- **Technologies:** [Facebook WhatsApp Desktop](https://agentprime.io/advisories/technology/facebook-whatsapp-desktop.md) · [Facebook WhatsApp for KaiOS](https://agentprime.io/advisories/technology/facebook-whatsapp-for-kaios.md) · [Facebook WhatsApp Business for iOS](https://agentprime.io/advisories/technology/facebook-whatsapp-business-for-ios.md) · [Facebook WhatsApp for iOS](https://agentprime.io/advisories/technology/facebook-whatsapp-for-ios.md) · [Facebook WhatsApp Business for Android](https://agentprime.io/advisories/technology/facebook-whatsapp-business-for-android.md) · [Facebook WhatsApp for Android](https://agentprime.io/advisories/technology/facebook-whatsapp-for-android.md)
- **Published:** 4 Jan 2022
- **Updated:** 22 May 2025
- **Reviewed by a person:** No

Published by the CVE Program (CNA: facebook) at 4 Jan 2022, 18:55 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Facebook. Product: WhatsApp Desktop.
  - affected: `unspecified to before v2.2146` (custom)
  - unaffected: `v2.2146 to before unspecified` (custom)
- Vendor: Facebook. Product: WhatsApp for KaiOS.
  - affected: `unspecified to before v2.2143` (custom)
  - unaffected: `v2.2143 to before unspecified` (custom)
- Vendor: Facebook. Product: WhatsApp Business for iOS.
  - affected: `unspecified to before v2.21.230` (custom)
  - unaffected: `v2.21.230 to before unspecified` (custom)
- Vendor: Facebook. Product: WhatsApp for iOS.
  - affected: `unspecified to before v2.21.230` (custom)
  - unaffected: `v2.21.230 to before unspecified` (custom)
- Vendor: Facebook. Product: WhatsApp Business for Android.
  - affected: `unspecified to before v2.21.23` (custom)
  - unaffected: `v2.21.23 to before unspecified` (custom)
- Vendor: Facebook. Product: WhatsApp for Android.
  - affected: `unspecified to before v2.21.23` (custom)
  - unaffected: `v2.21.23 to before unspecified` (custom)

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from ADP (CISA-ADP)

- **CISA KEV:** Not listed.
- **EPSS:** 0.013, the 70th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 4 Jan 2022. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2021-24042](https://www.cve.org/CVERecord?id=CVE-2021-24042)
- [NVD: CVE-2021-24042](https://nvd.nist.gov/vuln/detail/CVE-2021-24042)

### References from the CNA

- <https://www.whatsapp.com/security/advisories/2021/> (confirm)

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2021-24042>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2021-24042/>. Everything for agents: <https://agentprime.io/llms.txt>.