# CVE-2018-4266: Race condition in iOS, tvOS, watchOS, Safari, iTunes for Windows, iCloud for Windows

> A race condition in Apple operating systems and Safari allows attackers to execute arbitrary code, requiring updates to secure devices.

- **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/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:** Yes
- **Published:** 3 Apr 2019
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-4266, GHSA-fvcx-grrr-x536, UBUNTU-CVE-2018-4266

## What is CVE-2018-4266?

CVE-2018-4266 is a medium-severity vulnerability in Apple Icloud, published on 3 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A race condition was addressed with additional validation. This issue affected versions prior toiVersions prior to: OS 11.4.1, tvOS 11.4.1, watchOS 4.3.2, Safari 11.1.2, iTunes 12.8 for Windows, iCloud for Windows 7.6.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2018-4266?

It affects 6 products.


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

## How do I fix CVE-2018-4266?

Apply the vendor's patch.

## Is CVE-2018-4266 being exploited?

There is no known exploitation of CVE-2018-4266 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-2018-4266 and fix it if it is affected.

What it is: CVE-2018-4266 is a medium-severity vulnerability in Apple Icloud, published on 3 Apr 2019. 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-2018-4266 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-2018-4266/ (Markdown: https://insights.sbomify.com/CVE-2018-4266/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-4266
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-4266
- OSV: https://osv.dev/vulnerability/CVE-2018-4266

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-4266/
Summaries are generated and may contain mistakes; the official description above is the record.