# CVE-2021-24042: Memory corruption in WhatsApp Business for Android

> An out-of-bounds write vulnerability in WhatsApp allows attackers to execute arbitrary code when a user initiates a call to a malicious actor.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Jan 2022
- **Updated:** 22 May 2025
- **Also known as:** GHSA-mp5j-h5hx-cfxc

## What is CVE-2021-24042?

CVE-2021-24042 is a critical memory corruption vulnerability in Facebook WhatsApp Business for Android, published on 4 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-787 (Out-of-bounds Write), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2021-24042?

It affects 1 product.


Products: Whatsapp Whatsapp.

## How do I fix CVE-2021-24042?

No fix has been published for CVE-2021-24042 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-24042 being exploited?

There is no known exploitation of CVE-2021-24042 in the wild and no public exploit code.

## Other vulnerabilities in Facebook WhatsApp Business for Android

- [CVE-2019-3568](https://insights.sbomify.com/CVE-2019-3568/): WhatsApp VOIP Stack Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2019-18426](https://insights.sbomify.com/CVE-2019-18426/): WhatsApp Cross-Site Scripting (high 8.2, exploited in the wild)
- [CVE-2025-55177](https://insights.sbomify.com/CVE-2025-55177/): Meta Platforms WhatsApp Incorrect Authorization (medium 5.4, exploited in the wild)
- [CVE-2022-36934](https://insights.sbomify.com/CVE-2022-36934/): Integer overflow in WhatsApp Business for Android (critical 9.8)
- [CVE-2021-24041](https://insights.sbomify.com/CVE-2021-24041/): Memory corruption in WhatsApp Business for Android (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24042 and fix it if it is affected.

What it is: CVE-2021-24042 is a critical memory corruption vulnerability in Facebook WhatsApp Business for Android, published on 4 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-24042 in the wild and no public exploit code.

Affected product: Facebook WhatsApp Business for Android. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-24042/ (Markdown: https://insights.sbomify.com/CVE-2021-24042/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24042
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24042
- OSV: https://osv.dev/vulnerability/CVE-2021-24042

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-24042/
Summaries are generated and may contain mistakes; the official description above is the record.