# CVE-2020-9983: Memory corruption in Safari

> An out-of-bounds write in Safari allows attackers to execute arbitrary code via maliciously crafted web content.

- **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:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 16 Oct 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-9983, GHSA-6c43-4qm7-f3r6, UBUNTU-CVE-2020-9983

## What is CVE-2020-9983?

CVE-2020-9983 is a high-severity memory corruption vulnerability in Apple Icloud, published on 16 Oct 2020. 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 out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in Safari 14.0. Processing maliciously crafted web content may lead to code execution.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2020-9983?

It affects 8 products.


Products: Apple Icloud, Apple Ipados, Apple Iphone Os, Apple Itunes, Apple Safari, Apple Tvos, Apple Watchos, Fedoraproject Fedora.

## How do I fix CVE-2020-9983?

Upgrade to a fixed version.

## Is CVE-2020-9983 being exploited?

There is no known exploitation of CVE-2020-9983 in the wild and no public exploit code.

## Other vulnerabilities in Apple Icloud

- [CVE-2019-8506](https://insights.sbomify.com/CVE-2019-8506/): Apple Multiple Products Type Confusion (high 8.8, exploited in the wild)
- [CVE-2020-27932](https://insights.sbomify.com/CVE-2020-27932/): Apple Multiple Products Type Confusion (high 7.8, exploited in the wild)
- [CVE-2019-8746](https://insights.sbomify.com/CVE-2019-8746/): Memory corruption in iOS (critical 9.8)
- [CVE-2019-8749](https://insights.sbomify.com/CVE-2019-8749/): Memory corruption in iOS (critical 9.8)
- [CVE-2019-8756](https://insights.sbomify.com/CVE-2019-8756/): Memory corruption in iOS (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-9983 and fix it if it is affected.

What it is: CVE-2020-9983 is a high-severity memory corruption vulnerability in Apple Icloud, published on 16 Oct 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-9983 in the wild and no public exploit code.

Affected product: Apple Icloud. 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-2020-9983/ (Markdown: https://insights.sbomify.com/CVE-2020-9983/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-9983
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-9983
- OSV: https://osv.dev/vulnerability/CVE-2020-9983

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-9983/
Summaries are generated and may contain mistakes; the official description above is the record.