# CVE-2020-36521: Information disclosure in iCloud for Windows

> Processing a malicious TIFF file can cause denial of service or disclose memory contents in Apple operating systems and related applications.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 23 Sep 2022
- **Updated:** 22 May 2025
- **Also known as:** GHSA-f54m-mh6r-hqvj

## What is CVE-2020-36521?

CVE-2020-36521 is a high-severity vulnerability in Apple Icloud, published on 23 Sep 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

An out-of-bounds read was addressed with improved input validation. This issue is fixed in iCloud for Windows 11.4, iOS 14.0 and iPadOS 14.0, watchOS 7.0, tvOS 14.0, iCloud for Windows 7.21, iTunes for Windows 12.10.9. Processing a maliciously crafted tiff file may lead to a denial-of-service or potentially disclose memory contents.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2020-36521?

It affects 7 products.


Products: Apple Icloud, Apple Ipados, Apple Iphone Os, Apple Itunes, Apple Macos, Apple Tvos, Apple Watchos.

## How do I fix CVE-2020-36521?

No fix has been published for CVE-2020-36521 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-36521 being exploited?

There is no known exploitation of CVE-2020-36521 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-2020-36521 and fix it if it is affected.

What it is: CVE-2020-36521 is a high-severity vulnerability in Apple Icloud, published on 23 Sep 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-36521 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-2020-36521/ (Markdown: https://insights.sbomify.com/CVE-2020-36521/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36521
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36521
- OSV: https://osv.dev/vulnerability/CVE-2020-36521

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-36521/
Summaries are generated and may contain mistakes; the official description above is the record.