# CVE-2021-1939: Null dereference in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Wearables

> A null pointer dereference in Qualcomm Snapdragon firmware allows attackers to cause a denial of service when toggling preemption features.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2021
- **Updated:** 3 Aug 2024
- **Also known as:** 2826994, A-187073199, ASB-A-187073199, GHSA-j5qr-8rrw-8f9v

## What is CVE-2021-1939?

CVE-2021-1939 is a high-severity vulnerability in Qualcomm Apq8009 Firmware, published on 17 Sep 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Null pointer dereference occurs due to improper validation when the preemption feature enablement is toggled in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Wearables

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2021-1939?

It affects 108 products.


Products: Qualcomm Apq8009 Firmware, Qualcomm Apq8009w Firmware, Qualcomm Apq8017 Firmware, Qualcomm Apq8053 Firmware, Qualcomm Aqt1000 Firmware, Qualcomm Msm8909w Firmware, Qualcomm Msm8917 Firmware, Qualcomm Msm8953 Firmware, Qualcomm Qca4020 Firmware, Qualcomm Qca6174a Firmware, Qualcomm Qca6310 Firmware, Qualcomm Qca6335 Firmware, Qualcomm Qca6390 Firmware, Qualcomm Qca6391 Firmware, Qualcomm Qca6420 Firmware, Qualcomm Qca6421 Firmware, Qualcomm Qca6426 Firmware, Qualcomm Qca6430 Firmware, Qualcomm Qca6431 Firmware, Qualcomm Qca6436 Firmware and 88 more.

## How do I fix CVE-2021-1939?

Apply the vendor's patch.

## Is CVE-2021-1939 being exploited?

There is no known exploitation of CVE-2021-1939 in the wild and no public exploit code.

## Other vulnerabilities in Qualcomm Apq8009 Firmware

- [CVE-2021-1905](https://insights.sbomify.com/CVE-2021-1905/): Qualcomm Multiple Chipsets Use-After-Free (high 8.4, exploited in the wild)
- [CVE-2020-11261](https://insights.sbomify.com/CVE-2020-11261/): Qualcomm Multiple Chipsets Improper Input Validation (high 7.8, exploited in the wild)
- [CVE-2021-1906](https://insights.sbomify.com/CVE-2021-1906/): Qualcomm Multiple Chipsets Detection of Error Condition Without Action (medium 6.2, exploited in the wild)
- [CVE-2022-40510](https://insights.sbomify.com/CVE-2022-40510/): Buffer copy without checking size of input in Audio. (critical 9.8)
- [CVE-2022-22088](https://insights.sbomify.com/CVE-2022-22088/): Integer Overflow to Buffer Overflow in Bluetooth HOST (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1939 and fix it if it is affected.

What it is: CVE-2021-1939 is a high-severity vulnerability in Qualcomm Apq8009 Firmware, published on 17 Sep 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-2021-1939 in the wild and no public exploit code.

Affected product: Qualcomm Apq8009 Firmware. 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-2021-1939/ (Markdown: https://insights.sbomify.com/CVE-2021-1939/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1939
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1939
- OSV: https://osv.dev/vulnerability/CVE-2021-1939

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-1939/
Summaries are generated and may contain mistakes; the official description above is the record.