# CVE-2021-30661: Apple Multiple Products WebKit Storage Use-After-Free

> Attackers can execute arbitrary code by tricking users into visiting malicious web content in Safari or WebKit-based apps.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 3 Nov 2021 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 8 Sep 2021
- **Updated:** 21 Oct 2025
- **Also known as:** DEBIAN-CVE-2021-30661, GHSA-79qq-9x66-f5r5, UBUNTU-CVE-2021-30661

## What is CVE-2021-30661?

CVE-2021-30661 is a high-severity use after free vulnerability in Apple Ipados, published on 8 Sep 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2021-30661?

It affects 6 products.


Products: Apple Ipados, Apple Iphone Os, Apple Macos, Apple Safari, Apple Tvos, Apple Watchos.

## How do I fix CVE-2021-30661?

Upgrade to a fixed version. US federal agencies must fix it by 17 Nov 2021.

## Is CVE-2021-30661 being exploited?

Yes. Attackers have exploited CVE-2021-30661 in the wild since at least 3 Nov 2021.

## Other vulnerabilities in Apple Ipados

- [CVE-2025-43300](https://insights.sbomify.com/CVE-2025-43300/): Apple iOS, iPadOS, and macOS Out-of-Bounds Write (critical 10.0, exploited in the wild)
- [CVE-2025-24201](https://insights.sbomify.com/CVE-2025-24201/): Apple Multiple Products WebKit Out-of-Bounds Write (critical 10.0, exploited in the wild)
- [CVE-2025-24085](https://insights.sbomify.com/CVE-2025-24085/): Apple Multiple Products Use-After-Free (critical 10.0, exploited in the wild)
- [CVE-2025-31200](https://insights.sbomify.com/CVE-2025-31200/): Apple Multiple Products Memory Corruption (critical 9.8, exploited in the wild)
- [CVE-2025-31201](https://insights.sbomify.com/CVE-2025-31201/): Apple Multiple Products Arbitrary Read and Write (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-30661 and fix it if it is affected.

What it is: CVE-2021-30661 is a high-severity use after free vulnerability in Apple Ipados, published on 8 Sep 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: Yes. Attackers have exploited CVE-2021-30661 in the wild since at least 3 Nov 2021.

Affected product: Apple Ipados. 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-2021-30661/ (Markdown: https://insights.sbomify.com/CVE-2021-30661/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-30661
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-30661
- OSV: https://osv.dev/vulnerability/CVE-2021-30661

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-30661/
Summaries are generated and may contain mistakes; the official description above is the record.