# CVE-2021-0942: Memory corruption in Android

> An untrusted app can trigger an out-of-bounds read in the Android kernel via ioctl, potentially leading to code execution or privilege escalation.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** Yes
- **Published:** 13 Sep 2022
- **Updated:** 3 Aug 2024
- **Also known as:** A-238904312, ASB-A-238904312, GHSA-74fp-85wq-7rrv

## What is CVE-2021-0942?

CVE-2021-0942 is a critical memory corruption vulnerability in Google Android, published on 13 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The path in this case is a little bit convoluted. The end result is that via an ioctl an untrusted app can control the ui32PageIndex offset in the expression:sPA.uiAddr = page_to_phys(psOSPageArrayData->pagearray[ui32PageIndex]);With the current PoC this crashes as an OOB read. However, given that the OOB read value is ending up as the address field of a struct I think i seems plausible that this could lead to an OOB write if the attacker is able to cause the OOB read to pull an interesting kernel address. Regardless if this is a read or write, it is a High severity issue in the kernel.Product: AndroidVersions: Android SoCAndroid ID: A-238904312

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

## Which versions are affected by CVE-2021-0942?

It affects 1 product.


Products: Google Android.

## How do I fix CVE-2021-0942?

Apply the vendor's patch.

## Is CVE-2021-0942 being exploited?

There is no known exploitation of CVE-2021-0942 in the wild and no public exploit code.

## Other vulnerabilities in Google Android

- [CVE-2026-58704](https://insights.sbomify.com/CVE-2026-58704/): Google Pixel Improper Authorization (high 8.8, exploited in the wild)
- [CVE-2025-48543](https://insights.sbomify.com/CVE-2025-48543/): Android Runtime Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2023-35674](https://insights.sbomify.com/CVE-2023-35674/): Android Framework Privilege Escalation (high 8.8, exploited in the wild)
- [CVE-2025-48595](https://insights.sbomify.com/CVE-2025-48595/): Android Framework Integer Overflow (high 8.4, exploited in the wild)
- [CVE-2024-32896](https://insights.sbomify.com/CVE-2024-32896/): Android Pixel Privilege Escalation (high 8.1, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-0942 and fix it if it is affected.

What it is: CVE-2021-0942 is a critical memory corruption vulnerability in Google Android, published on 13 Sep 2022. 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-2021-0942 in the wild and no public exploit code.

Affected product: Google Android. 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-2021-0942/ (Markdown: https://insights.sbomify.com/CVE-2021-0942/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-0942
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-0942
- OSV: https://osv.dev/vulnerability/CVE-2021-0942

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-0942/
Summaries are generated and may contain mistakes; the official description above is the record.