# CVE-2020-1901: Denial of service in WhatsApp for iOS

> An attacker can cause WhatsApp for iOS to freeze by sending a large text message containing URLs, requiring users to upgrade to the latest version.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Oct 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-gqr2-r72f-2848

## What is CVE-2020-1901?

CVE-2020-1901 is a medium-severity denial of service vulnerability in Facebook WhatsApp for iOS, published on 6 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Receiving a large text message containing URLs in WhatsApp for iOS prior to v2.20.91.4 could have caused the application to freeze while processing the message.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2020-1901?

It affects 1 product.


Products: Whatsapp Whatsapp.

## How do I fix CVE-2020-1901?

No fix has been published for CVE-2020-1901 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-1901 being exploited?

There is no known exploitation of CVE-2020-1901 in the wild and no public exploit code.

## Other vulnerabilities in Facebook WhatsApp 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-2020-1901 and fix it if it is affected.

What it is: CVE-2020-1901 is a medium-severity denial of service vulnerability in Facebook WhatsApp for iOS, published on 6 Oct 2020. 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-2020-1901 in the wild and no public exploit code.

Affected product: Facebook WhatsApp 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-2020-1901/ (Markdown: https://insights.sbomify.com/CVE-2020-1901/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1901
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1901
- OSV: https://osv.dev/vulnerability/CVE-2020-1901

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-1901/
Summaries are generated and may contain mistakes; the official description above is the record.