# CVE-2021-30845: Information disclosure in macOS

> A local attacker can read kernel memory due to an out-of-bounds read in macOS, potentially exposing sensitive system data.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Oct 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-hfx3-2rg5-4pq4

## What is CVE-2021-30845?

CVE-2021-30845 is a medium-severity vulnerability in Apple Macos, published on 19 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in macOS Big Sur 11.6. A local user may be able to read kernel memory.

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

## Which versions are affected by CVE-2021-30845?

It affects 1 product.


Products: Apple Macos.

## How do I fix CVE-2021-30845?

No fix has been published for CVE-2021-30845 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-30845 being exploited?

There is no known exploitation of CVE-2021-30845 in the wild and no public exploit code.

## Other vulnerabilities in Apple Macos

- [CVE-2026-65400](https://insights.sbomify.com/CVE-2026-65400/): Apple macOS Improper Authentication (critical 9.8, exploited in the wild)
- [CVE-2024-44146](https://insights.sbomify.com/CVE-2024-44146/): Security feature bypass in macOS (critical 10.0)
- [CVE-2024-44148](https://insights.sbomify.com/CVE-2024-44148/): Security feature bypass in macOS (critical 10.0)
- [CVE-2023-38586](https://insights.sbomify.com/CVE-2023-38586/): Security feature bypass in macOS (critical 10.0)
- [CVE-2023-40455](https://insights.sbomify.com/CVE-2023-40455/): Security feature bypass in macOS (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-30845 and fix it if it is affected.

What it is: CVE-2021-30845 is a medium-severity vulnerability in Apple Macos, published on 19 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-30845 in the wild and no public exploit code.

Affected product: Apple Macos. 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-2021-30845/ (Markdown: https://insights.sbomify.com/CVE-2021-30845/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-30845
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-30845
- OSV: https://osv.dev/vulnerability/CVE-2021-30845

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-30845/
Summaries are generated and may contain mistakes; the official description above is the record.