# CVE-2019-20374: Cross-site scripting in n/a

> An XSS vulnerability in Typora allows remote code execution via malicious Mermaid code blocks when opening files.

- **Severity:** High 8.3 (`CVSS:3.0/AC:H/AV:N/A:H/C:H/I:H/PR:N/S:C/UI:R`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 9 Jan 2020
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-6r2r-v362-h96w

## What is CVE-2019-20374?

CVE-2019-20374 is a high-severity cross-site scripting vulnerability in n/a, published on 9 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A mutation cross-site scripting (XSS) issue in Typora through 0.9.9.31.2 on macOS and through 0.9.81 on Linux leads to Remote Code Execution through Mermaid code blocks. To exploit this vulnerability, one must open a file in Typora. The XSS vulnerability is then triggered due to improper HTML sanitization. Given that the application is based on the Electron framework, the XSS leads to remote code execution in an unsandboxed environment.

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

## Which versions are affected by CVE-2019-20374?

It affects 1 product.


Products: Typora Typora.

## How do I fix CVE-2019-20374?

No fix has been published for CVE-2019-20374 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-20374 being exploited?

There is no known exploitation of CVE-2019-20374 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2023-2317](https://insights.sbomify.com/CVE-2023-2317/): Typora DOM-Based Cross-site Scripting leading to Remote Code Execution (high 8.6)
- [CVE-2019-12172](https://insights.sbomify.com/CVE-2019-12172/): Path traversal in n/a (high 7.8)
- [CVE-2019-12137](https://insights.sbomify.com/CVE-2019-12137/): Path traversal in n/a (high 7.8)
- [CVE-2020-18336](https://insights.sbomify.com/CVE-2020-18336/): Cross-site scripting in n/a (high 7.4)
- [CVE-2023-2316](https://insights.sbomify.com/CVE-2023-2316/): Typora Local File Disclosure (high 7.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-20374 and fix it if it is affected.

What it is: CVE-2019-20374 is a high-severity cross-site scripting vulnerability in n/a, published on 9 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-20374 in the wild and no public exploit code.

Affected product: n/a. 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-2019-20374/ (Markdown: https://insights.sbomify.com/CVE-2019-20374/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-20374
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-20374
- OSV: https://osv.dev/vulnerability/CVE-2019-20374

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-20374/
Summaries are generated and may contain mistakes; the official description above is the record.