# CVE-2021-30952: Apple Multiple Products Integer Overflow or Wraparound

> Processing maliciously crafted web content may lead to arbitrary code execution due to an integer overflow in Apple's web rendering engine.

- **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 5 Mar 2026 (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:** 24 Aug 2021
- **Updated:** 6 Mar 2026
- **Also known as:** DEBIAN-CVE-2021-30952, UBUNTU-CVE-2021-30952

## What is CVE-2021-30952?

CVE-2021-30952 is a high-severity vulnerability in Apple Ipados, published on 24 Aug 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

An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2021-30952?

It affects 10 products.


Products: Apple Ipados, Apple Iphone Os, Apple Macos, Apple Safari, Apple Tvos, Apple Watchos, Debian Debian Linux, Fedoraproject Fedora, Webkitgtk Webkitgtk, Wpewebkit Wpe Webkit.

## How do I fix CVE-2021-30952?

Upgrade to a fixed version. US federal agencies must fix it by 26 Mar 2026.

## Is CVE-2021-30952 being exploited?

Yes. Attackers have exploited CVE-2021-30952 in the wild since at least 5 Mar 2026.

## 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-2021-30952 and fix it if it is affected.

What it is: CVE-2021-30952 is a high-severity vulnerability in Apple Ipados, published on 24 Aug 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-2021-30952 in the wild since at least 5 Mar 2026.

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-2021-30952/ (Markdown: https://insights.sbomify.com/CVE-2021-30952/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-30952
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-30952
- OSV: https://osv.dev/vulnerability/CVE-2021-30952

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-30952/
Summaries are generated and may contain mistakes; the official description above is the record.