# CVE-2021-3675: synaTEE.signed.dll Out-Of-Bounds Heap Write

> A local attacker can exploit an out-of-bounds heap write in the Synaptics Fingerprint Driver to potentially compromise confidentiality.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Jun 2022
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-mqp4-mr97-536g

## What is CVE-2021-3675?

CVE-2021-3675 is a medium-severity memory corruption vulnerability in Synaptics Fingerprint Driver, published on 16 Jun 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Improper Input Validation vulnerability in synaTEE.signed.dll of Synaptics Fingerprint Driver allows a local authorized attacker to overwrite a heap tag, with potential loss of confidentiality. This issue affects: Synaptics Synaptics Fingerprint Driver 5.1.xxx.26 versions prior to xxx=340 on x86/64; 5.2.xxxx.26 versions prior to xxxx=3541 on x86/64; 5.2.2xx.26 versions prior to xx=29 on x86/64; 5.2.3xx.26 versions prior to xx=25 on x86/64; 5.3.xxxx.26 versions prior to xxxx=3543 on x86/64; 5.5.xx.1058 versions prior to xx=44 on x86/64; 5.5.xx.1102 versions prior to xx=34 on x86/64; 5.5.xx.1116 versions prior to xx=14 on x86/64; 6.0.xx.1104 versions prior to xx=50 on x86/64; 6.0.xx.1108 versions prior to xx=31 on x86/64; 6.0.xx.1111 versions prior to xx=58 on x86/64.

Weakness: CWE-787 (Out-of-bounds Write), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2021-3675?

It affects 1 product.


Products: Synaptics Fingerprint Driver.

## How do I fix CVE-2021-3675?

No fix has been published for CVE-2021-3675 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-3675 being exploited?

There is no known exploitation of CVE-2021-3675 in the wild and no public exploit code.

## Other vulnerabilities in Synaptics Fingerprint Driver

- [CVE-2023-6482](https://insights.sbomify.com/CVE-2023-6482/): Encryption key derived from static host information (medium 5.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3675 and fix it if it is affected.

What it is: CVE-2021-3675 is a medium-severity memory corruption vulnerability in Synaptics Fingerprint Driver, published on 16 Jun 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-2021-3675 in the wild and no public exploit code.

Affected product: Synaptics Fingerprint Driver. 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-2021-3675/ (Markdown: https://insights.sbomify.com/CVE-2021-3675/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3675
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3675
- OSV: https://osv.dev/vulnerability/CVE-2021-3675

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3675/
Summaries are generated and may contain mistakes; the official description above is the record.