GHSA-w32g-5hqp-gg6q Cross-Site Scripting in mermaid
An attacker can execute arbitrary JavaScript in a victim's browser by providing malicious input to the mermaid diagramming library.
- 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
What is GHSA-w32g-5hqp-gg6q?
GHSA-w32g-5hqp-gg6q is a cross-site scripting vulnerability in mermaid, published on 2 Sep 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
Versions of mermaid prior to 8.2.3 are vulnerable to Cross-Site Scripting. If malicious input such as A["<img src=invalid onerror=alert('XSS')></img>"] is provided to the application, it will execute the code instead of rendering it as text due to improper output encoding.
Recommendation
Upgrade to version 8.2.3 or later
Which versions are affected by GHSA-w32g-5hqp-gg6q?
2 open source packages ship an affected version, including mermaid.
| Package | Affected | Fixed in |
|---|---|---|
mermaid npm | All versions | 8.2.3 |
mermaid npm | All versions | 8.2.3 |
How do I fix GHSA-w32g-5hqp-gg6q?
Upgrade mermaid to 8.2.3 or later.
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 GHSA-w32g-5hqp-gg6q being exploited?
There is no known exploitation of GHSA-w32g-5hqp-gg6q in the wild and no public exploit code.