# CVE-2021-38788: Denial of service in n/a

> Malicious apps can force-stop other background applications by manipulating the background service whitelist, causing denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Jan 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-qc2p-7ph7-28gf

## What is CVE-2021-38788?

CVE-2021-38788 is a high-severity denial of service vulnerability in n/a, published on 19 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Background service in Allwinner R818 SoC Android Q SDK V1.0 is used to manage background applications. Malicious apps can use the interface provided by the service to set the number of applications allowed to run in the background to 0 and add themselves to the whitelist, so that once other applications enter the background, they will be forcibly stopped by the system, causing a denial of service.

## Which versions are affected by CVE-2021-38788?

It affects 1 product.


Products: Allwinnertech Android Q Sdk.

## How do I fix CVE-2021-38788?

No fix has been published for CVE-2021-38788 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-38788 being exploited?

There is no known exploitation of CVE-2021-38788 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-38786](https://insights.sbomify.com/CVE-2021-38786/): Null dereference in n/a (high 7.5)
- [CVE-2021-38787](https://insights.sbomify.com/CVE-2021-38787/): Integer overflow in n/a (high 7.5)
- [CVE-2021-38789](https://insights.sbomify.com/CVE-2021-38789/): Missing authorization in n/a (high 7.5)
- [CVE-2021-38783](https://insights.sbomify.com/CVE-2021-38783/): Memory corruption in n/a (high 7.5)
- [CVE-2021-38784](https://insights.sbomify.com/CVE-2021-38784/): Null dereference in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-38788 and fix it if it is affected.

What it is: CVE-2021-38788 is a high-severity denial of service vulnerability in n/a, published on 19 Jan 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-2021-38788 in the wild and no public exploit code.

Affected product: n/a. 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-2021-38788/ (Markdown: https://insights.sbomify.com/CVE-2021-38788/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-38788
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-38788
- OSV: https://osv.dev/vulnerability/CVE-2021-38788

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-38788/
Summaries are generated and may contain mistakes; the official description above is the record.