# CVE-2021-0331: Security feature bypass in Android

> An insecure default value in Android's notification access confirmation allows local attackers to perform overlay attacks and escalate privileges.

- **Severity:** High 7.3 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 10 Feb 2021
- **Updated:** 3 Aug 2024
- **Also known as:** A-170731783, ASB-A-170731783, GHSA-9vc6-7g98-392v

## What is CVE-2021-0331?

CVE-2021-0331 is a high-severity vulnerability in Google Android, published on 10 Feb 2021. 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

In onCreate of NotificationAccessConfirmationActivity.java, there is a possible overlay attack due to an insecure default value. This could lead to local escalation of privilege and notification access with User execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-9 Android-10 Android-11 Android-8.1Android ID: A-170731783

Weakness: CWE-1021 (Improper Restriction of Rendered UI Layers or Frames)

## Which versions are affected by CVE-2021-0331?

It affects 1 product.


Products: Google Android.

## How do I fix CVE-2021-0331?

Apply the vendor's patch.

## Is CVE-2021-0331 being exploited?

There is no known exploitation of CVE-2021-0331 in the wild and no public exploit code.

Public exploit code:

- https://github.com/Satheesh575555/packages_apps_Settings_AOSP10_r33_CVE-2021-0331 (github_poc): https://github.com/Satheesh575555/packages_apps_Settings_AOSP10_r33_CVE-2021-0331

## 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-2021-0331 and fix it if it is affected.

What it is: CVE-2021-0331 is a high-severity vulnerability in Google Android, published on 10 Feb 2021. 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-2021-0331 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-2021-0331/ (Markdown: https://insights.sbomify.com/CVE-2021-0331/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-0331
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-0331
- OSV: https://osv.dev/vulnerability/CVE-2021-0331

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-0331/
Summaries are generated and may contain mistakes; the official description above is the record.