CVE-2024-38527: ZenUML is JavaScript-based diagramming tool that requires no server, using Markdown-inspired text definitions and a renderer to create and modify sequ...

Description

ZenUML is JavaScript-based diagramming tool that requires no server, using Markdown-inspired text definitions and a renderer to create and modify sequence diagrams. Markdown-based comments in the ZenUML diagram syntax are susceptible to Cross-site Scripting (XSS). The comment feature allows the user to attach small notes for reference. This feature allows the user to enter in their comment in markdown comment, allowing them to use common markdown features, such as `**` for bolded text. However, the markdown text is currently not sanitized before rendering, allowing an attacker to enter a malicious payload for the comment which leads to XSS. This puts existing applications that use ZenUML unsandboxed at risk of arbitrary JavaScript execution when rendering user-controlled diagrams. This vulnerability was patched in version 3.23.25,

Metrics

CVSS 3.1

5.4/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

EPSS Probability

0.38%

29.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: Jun 26, 2024
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2024-38527?

ZenUML is JavaScript-based diagramming tool that requires no server, using Markdown-inspired text definitions and a renderer to create and modify sequence diagrams. Markdown-based comments in the ZenUML diagram syntax are susceptible to Cross-site Scripting (XSS). The comment feature allows the user to attach small notes for reference. This feature allows the user to enter in their comment in markdown comment, allowing them to use common markdown features, such as `**` for bolded text. However, the markdown text is currently not sanitized before rendering, allowing an attacker to enter a malicious payload for the comment which leads to XSS. This puts existing applications that use ZenUML unsandboxed at risk of arbitrary JavaScript execution when rendering user-controlled diagrams. This vulnerability was patched in version 3.23.25,

How severe is CVE-2024-38527?

CVE-2024-38527 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.

How do I fix CVE-2024-38527?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.