# CVE-2018-4377: Cross-site scripting in iOS, watchOS, Safari, iTunes for Windows, iCloud for Windows

> An attacker can execute arbitrary scripts in Safari via a cross-site scripting vulnerability, requiring users to update their Apple software.

- **Severity:** Medium 6.1 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **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:** No
- **Published:** 3 Apr 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-62wm-r84h-xppr

## What is CVE-2018-4377?

CVE-2018-4377 is a medium-severity cross-site scripting vulnerability in Apple Icloud, published on 3 Apr 2019. 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 cross-site scripting issue existed in Safari. This issue was addressed with improved URL validation. This issue affected versions prior to iOS 12.1, watchOS 5.1, Safari 12.0.1, iTunes 12.9.1, iCloud for Windows 7.8.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2018-4377?

It affects 5 products.


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

## How do I fix CVE-2018-4377?

No fix has been published for CVE-2018-4377 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-4377 being exploited?

There is no known exploitation of CVE-2018-4377 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-2018-4377 and fix it if it is affected.

What it is: CVE-2018-4377 is a medium-severity cross-site scripting vulnerability in Apple Icloud, published on 3 Apr 2019. 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-2018-4377 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-2018-4377/ (Markdown: https://insights.sbomify.com/CVE-2018-4377/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-4377
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-4377
- OSV: https://osv.dev/vulnerability/CVE-2018-4377

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-4377/
Summaries are generated and may contain mistakes; the official description above is the record.