# CVE-2020-3951: Memory corruption in VMware Workstation and Horizon Client for Windows

> A heap overflow in Cortado Thinprint allows guest users to cause a denial of service on the host system when virtual printing is enabled.

- **Severity:** Low 3.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:L`)
- **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:** 17 Mar 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-gj73-m2qr-829r

## What is CVE-2020-3951?

CVE-2020-3951 is a low-severity memory corruption vulnerability in Vmware Workstation, published on 17 Mar 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

VMware Workstation (15.x before 15.5.2) and Horizon Client for Windows (5.x and prior before 5.4.0) contain a denial-of-service vulnerability due to a heap-overflow issue in Cortado Thinprint. Attackers with non-administrative access to a guest VM with virtual printing enabled may exploit this issue to create a denial-of-service condition of the Thinprint service running on the system where Workstation or Horizon Client is installed.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2020-3951?

It affects 2 products.


Products: Vmware Horizon Client, Vmware Workstation.

## How do I fix CVE-2020-3951?

No fix has been published for CVE-2020-3951 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3951 being exploited?

There is no known exploitation of CVE-2020-3951 in the wild and no public exploit code.

## Other vulnerabilities in Vmware Workstation

- [CVE-2020-3961](https://insights.sbomify.com/CVE-2020-3961/): Privilege escalation in VMware Horizon Client for Windows (high 7.8)
- [CVE-2019-5543](https://insights.sbomify.com/CVE-2019-5543/): Privilege escalation in VMware Horizon Client for Windows (high 7.8)
- [CVE-2018-6964](https://insights.sbomify.com/CVE-2018-6964/): Privilege escalation in Horizon Client for Linux (high 7.8)
- [CVE-2020-3991](https://insights.sbomify.com/CVE-2020-3991/): Path traversal in VMware Horizon Client for Windows (high 7.1)
- [CVE-2021-21987](https://insights.sbomify.com/CVE-2021-21987/): Information disclosure in VMware Workstation Pro / Player (Workstation), VMware Horizon Client for Windows (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3951 and fix it if it is affected.

What it is: CVE-2020-3951 is a low-severity memory corruption vulnerability in Vmware Workstation, published on 17 Mar 2020. 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-2020-3951 in the wild and no public exploit code.

Affected product: Vmware Workstation. 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-2020-3951/ (Markdown: https://insights.sbomify.com/CVE-2020-3951/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3951
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3951
- OSV: https://osv.dev/vulnerability/CVE-2020-3951

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3951/
Summaries are generated and may contain mistakes; the official description above is the record.