# CVE-2023-37259: Cross site scripting in Export Chat feature

> A malicious homeserver can inject scripts into the Export Chat feature, potentially leaking message contents to attackers.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:C/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 18 Jul 2023
- **Updated:** 18 Oct 2024
- **Also known as:** GHSA-c9vx-2g7w-rp65, openSUSE-SU-2024:13054-1, openSUSE-SU-2024:13055-1

## What is CVE-2023-37259?

CVE-2023-37259 is a medium-severity cross-site scripting vulnerability in matrix-org matrix-react-sdk, published on 18 Jul 2023. 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. The Export Chat feature includes certain attacker-controlled elements in the generated document without sufficient escaping, leading to stored Cross site scripting (XSS). Since the Export Chat feature generates a separate document, an attacker can only inject code run from the `null` origin, restricting the impact. However, the attacker can still potentially use the XSS to leak message contents. A malicious homeserver is a potential attacker since the affected inputs are controllable server-side. This issue has been addressed in commit `22fcd34c60` which is included in release version 3.76.0. Users are advised to upgrade. The only known workaround for this issue is to disable or to not use the Export Chat feature.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2023-37259?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `matrix-react-sdk` | npm | From 3.32.0 | 3.76.0 |
| `matrix-react-sdk` | npm | From 3.32.0 | 3.76.0 |
| `element-desktop` | openSUSE:Tumbleweed | All versions | 1.11.36-1.1 |
| `element-web` | openSUSE:Tumbleweed | All versions | 1.11.36-1.1 |

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

## How do I fix CVE-2023-37259?

Upgrade matrix-react-sdk to 3.76.0 or later.

## Is CVE-2023-37259 being exploited?

There is no known exploitation of CVE-2023-37259 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-2023-30609](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-2021-32622](https://insights.sbomify.com/CVE-2021-32622/): File upload local preview can run embedded scripts after user interaction (medium 4.2)
- [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-2023-37259 and fix it if it is affected.

What it is: CVE-2023-37259 is a medium-severity cross-site scripting vulnerability in matrix-org matrix-react-sdk, published on 18 Jul 2023. 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-2023-37259 in the wild and no public exploit code.

Affected packages and fixed versions:
- matrix-react-sdk (npm): affected from 3.32.0; fixed in 3.76.0
- matrix-react-sdk (npm): affected from 3.32.0; fixed in 3.76.0

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-2023-37259/ (Markdown: https://insights.sbomify.com/CVE-2023-37259/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-37259
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-37259
- OSV: https://osv.dev/vulnerability/CVE-2023-37259

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-37259/
Summaries are generated and may contain mistakes; the official description above is the record.