# CVE-2018-20655: Memory corruption in WhatsApp Business for iOS

> A stack-based buffer overflow in WhatsApp for iOS allows remote code execution via malicious packets during incoming calls.

- **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:** 14 Jun 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-99ph-jqg7-g9v9

## What is CVE-2018-20655?

CVE-2018-20655 is a critical memory corruption vulnerability in Facebook WhatsApp Business for iOS, published on 14 Jun 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

When receiving calls using WhatsApp for iOS, a missing size check when parsing a sender-provided packet allowed for a stack-based overflow. This issue affects WhatsApp for iOS prior to v2.18.90.24 and WhatsApp Business for iOS prior to v2.18.90.24.

Weakness: CWE-787 (Out-of-bounds Write), CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2018-20655?

It affects 2 products.


Products: Whatsapp Whatsapp, Whatsapp Whatsapp Business.

## How do I fix CVE-2018-20655?

No fix has been published for CVE-2018-20655 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-20655 being exploited?

There is no known exploitation of CVE-2018-20655 in the wild and no public exploit code.

## Other vulnerabilities in Facebook WhatsApp Business for iOS

- [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-2021-24042](https://insights.sbomify.com/CVE-2021-24042/): Memory corruption in WhatsApp Business for Android (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-20655 and fix it if it is affected.

What it is: CVE-2018-20655 is a critical memory corruption vulnerability in Facebook WhatsApp Business for iOS, published on 14 Jun 2019. 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-2018-20655 in the wild and no public exploit code.

Affected product: Facebook WhatsApp Business for iOS. 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-2018-20655/ (Markdown: https://insights.sbomify.com/CVE-2018-20655/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-20655
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-20655
- OSV: https://osv.dev/vulnerability/CVE-2018-20655

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-20655/
Summaries are generated and may contain mistakes; the official description above is the record.