# CVE-2021-32622: File upload local preview can run embedded scripts after user interaction

> Local file previews in Matrix React SDK can execute embedded scripts after user interaction, allowing local code execution during upload.

- **Severity:** Medium 4.2 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 17 May 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-8796-gc9j-63rv, GHSA-cg57-p69r-3m7p

## What is CVE-2021-32622?

CVE-2021-32622 is a medium-severity cross-site scripting vulnerability in matrix-org matrix-react-sdk, published on 17 May 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Matrix-React-SDK is a react-based SDK for inserting a Matrix chat/voip client into a web page. Before version 3.21.0, when uploading a file, the local file preview can lead to execution of scripts embedded in the uploaded file. This can only occur after several user interactions to open the preview in a separate tab. This only impacts the local user while in the process of uploading. It cannot be exploited remotely or by other users. This vulnerability is patched in version 3.21.0.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2021-32622?

4 open source packages ship an affected version, including matrix-react-sdk. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `matrix-react-sdk` | npm | All versions | 3.21.0 |
| `matrix-react-sdk` | npm | All versions | 3.21.0 |
| `matrix-react-sdk` | npm | All versions | 3.21.0 |
| `matrix-react-sdk` | npm | All versions | 3.21.0 |

Products: Matrix-React-Sdk Project Matrix-React-Sdk.

## How do I fix CVE-2021-32622?

Upgrade matrix-react-sdk to 3.21.0 or later.

## Is CVE-2021-32622 being exploited?

There is no known exploitation of CVE-2021-32622 in the wild and no public exploit code.

## Other vulnerabilities in matrix-org matrix-react-sdk

- [CVE-2023-28103](https://insights.sbomify.com/CVE-2023-28103/): Prototype pollution in matrix-react-sdk (high 8.2)
- [CVE-2023-37259](https://insights.sbomify.com/CVE-2023-37259/): Cross site scripting in Export Chat feature (medium 6.1)
- [CVE-2023-30609](https://insights.sbomify.com/CVE-2023-30609/): matrix-react-sdk vulnerable to HTML injection in search results via plaintext message highlighting (medium 5.4)
- [CVE-2021-21320](https://insights.sbomify.com/CVE-2021-21320/): User content sandbox can be confused into opening arbitrary documents (low 2.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-32622 and fix it if it is affected.

What it is: CVE-2021-32622 is a medium-severity cross-site scripting vulnerability in matrix-org matrix-react-sdk, published on 17 May 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-32622 in the wild and no public exploit code.

Affected packages and fixed versions:
- matrix-react-sdk (npm): affected all versions; fixed in 3.21.0
- matrix-react-sdk (npm): affected all versions; fixed in 3.21.0
- matrix-react-sdk (npm): affected all versions; fixed in 3.21.0
- matrix-react-sdk (npm): affected all versions; fixed in 3.21.0

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-2021-32622/ (Markdown: https://insights.sbomify.com/CVE-2021-32622/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-32622
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-32622
- OSV: https://osv.dev/vulnerability/CVE-2021-32622

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-32622/
Summaries are generated and may contain mistakes; the official description above is the record.