# CVE-2021-1761: Denial of service in iOS and iPadOS

> A remote attacker can cause a denial of service on Apple operating systems, requiring users to apply security updates.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 2 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-jxf4-w4m5-h6gr

## What is CVE-2021-1761?

CVE-2021-1761 is a high-severity denial of service vulnerability in Apple Ipad Os, published on 2 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, watchOS 7.3, tvOS 14.4, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause a denial of service.

## Which versions are affected by CVE-2021-1761?

It affects 6 products.


Products: Apple Ipad Os, Apple Iphone Os, Apple Mac Os X, Apple Macos, Apple Tvos, Apple Watchos.

## How do I fix CVE-2021-1761?

No fix has been published for CVE-2021-1761 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-1761 being exploited?

There is no known exploitation of CVE-2021-1761 in the wild and no public exploit code.

## Other vulnerabilities in Apple Ipad Os

- [CVE-2021-1794](https://insights.sbomify.com/CVE-2021-1794/): Memory corruption in iOS and iPadOS (critical 9.8)
- [CVE-2021-1795](https://insights.sbomify.com/CVE-2021-1795/): Memory corruption in iOS and iPadOS (critical 9.8)
- [CVE-2021-1796](https://insights.sbomify.com/CVE-2021-1796/): Memory corruption in iOS and iPadOS (critical 9.8)
- [CVE-2021-1818](https://insights.sbomify.com/CVE-2021-1818/): Memory corruption in iOS and iPadOS (critical 9.8)
- [CVE-2024-23255](https://insights.sbomify.com/CVE-2024-23255/): Auth bypass in iOS and iPadOS (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1761 and fix it if it is affected.

What it is: CVE-2021-1761 is a high-severity denial of service vulnerability in Apple Ipad Os, published on 2 Apr 2021. 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-2021-1761 in the wild and no public exploit code.

Affected product: Apple Ipad Os. 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-2021-1761/ (Markdown: https://insights.sbomify.com/CVE-2021-1761/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1761
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1761
- OSV: https://osv.dev/vulnerability/CVE-2021-1761

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-1761/
Summaries are generated and may contain mistakes; the official description above is the record.