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

High 8.3 Published 9 Jan 2020 Updated 5 Aug 2024

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

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: None listed

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

Which versions are affected by CVE-2019-20374?

It affects 1 product.

Products include 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.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2019-20374 being exploited?

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

Sources

Also known as GHSA-6r2r-v362-h96w.