# CVE-2021-35133: Use after free in Snapdragon Connectivity, Snapdragon Industrial IOT, Snapdragon Mobile

> A use-after-free vulnerability in the Qualcomm synx driver allows attackers to execute arbitrary code or escalate privileges via multiple release calls.

- **Severity:** Medium 6.7 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Sep 2022
- **Updated:** 4 Aug 2024
- **Also known as:** 3031134, A-213241418, GHSA-5wcq-2m8r-q254, PUB-A-213241418

## What is CVE-2021-35133?

CVE-2021-35133 is a medium-severity use after free vulnerability in Qualcomm Ar8035 Firmware, published on 2 Sep 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Use after free in the synx driver issue while performing other functions during multiple invocation of synx release calls in Snapdragon Connectivity, Snapdragon Industrial IOT, Snapdragon Mobile

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2021-35133?

It affects 36 products.


Products: Qualcomm Ar8035 Firmware, Qualcomm Qca6174a Firmware, Qualcomm Qca6391 Firmware, Qualcomm Qca8081 Firmware, Qualcomm Qca8337 Firmware, Qualcomm Qca9377 Firmware, Qualcomm Qcm6490 Firmware, Qualcomm Qcs6490 Firmware, Qualcomm Sd480 Firmware, Qualcomm Sd780g Firmware, Qualcomm Sd888 5g Firmware, Qualcomm Sd 8 Gen1 5g Firmware, Qualcomm Sdx12 Firmware, Qualcomm Sdx65 Firmware, Qualcomm Sm7450 Firmware, Qualcomm Sm8475 Firmware, Qualcomm Sm8475p Firmware, Qualcomm Wcd9335 Firmware, Qualcomm Wcd9341 Firmware, Qualcomm Wcd9370 Firmware and 16 more.

## How do I fix CVE-2021-35133?

Apply the vendor's patch.

## Is CVE-2021-35133 being exploited?

There is no known exploitation of CVE-2021-35133 in the wild and no public exploit code.

## Other vulnerabilities in Qualcomm Ar8035 Firmware

- [CVE-2023-33106](https://insights.sbomify.com/CVE-2023-33106/): Qualcomm Multiple Chipsets Use of Out-of-Range Pointer Offset (high 8.4, exploited in the wild)
- [CVE-2024-45569](https://insights.sbomify.com/CVE-2024-45569/): Improper Validation of Array Index in WLAN Host Communication (critical 9.8)
- [CVE-2024-21473](https://insights.sbomify.com/CVE-2024-21473/): Improper Input Validation in WIN SON (critical 9.8)
- [CVE-2023-28582](https://insights.sbomify.com/CVE-2023-28582/): Buffer Copy Without Checking Size of Input in Data Modem (critical 9.8)
- [CVE-2023-43552](https://insights.sbomify.com/CVE-2023-43552/): Use After Free in WLAN Host Communication (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-35133 and fix it if it is affected.

What it is: CVE-2021-35133 is a medium-severity use after free vulnerability in Qualcomm Ar8035 Firmware, published on 2 Sep 2022. 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-2021-35133 in the wild and no public exploit code.

Affected product: Qualcomm Ar8035 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-2021-35133/ (Markdown: https://insights.sbomify.com/CVE-2021-35133/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-35133
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-35133
- OSV: https://osv.dev/vulnerability/CVE-2021-35133

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-35133/
Summaries are generated and may contain mistakes; the official description above is the record.