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fix(front): Enable mermaid rendering on reports tab #618

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Merged
merged 4 commits into from
Oct 1, 2025
Merged

fix(front): Enable mermaid rendering on reports tab #618

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e9ef684
fix(front): Enable mermaid rendering on reports tab
hamir-suspect Sep 29, 2025
c75c12a
fix(front): Remove test that can't work
hamir-suspect Sep 30, 2025
129c5ad
fix: linting
hamir-suspect Sep 30, 2025
547dbe2
Merge branch 'main' into has/front/markdown-report
hamir-suspect Oct 1, 2025
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39 changes: 33 additions & 6 deletions front/assets/js/report/index.tsx
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@ import DOMPurify from 'dompurify';
import * as toolbox from "js/toolbox";
import { useEffect, useState } from "preact/hooks";

Mermaid.initialize({ startOnLoad: false, theme: `default`, securityLevel: `strict` });
Mermaid.initialize({ startOnLoad: false, theme: `default`, securityLevel: `sandbox` });
const md = MarkdownIt({
html: true,
linkify: false,
Expand Down Expand Up @@ -83,6 +83,21 @@ const MarkdownBody = (props: { markdown: string, }) => {
}, [props.markdown]);

const renderedHtml = md.render(props.markdown);
// Note: Sanitization is applied here before mermaid rendering. Some mermaid-specific tags
// (like those generated by markdown-it-textual-uml) are intentionally not included in ALLOWED_TAGS
// because they're processed by Mermaid.run() after sanitization.
// Additionally, Mermaid provides two more security layers:
// 1. It uses DOMPurify internally for sanitizing diagram content
// 2. With securityLevel: 'sandbox' configured above, it renders each diagram in a sandboxed iframe
// First, configure DOMPurify hooks
DOMPurify.addHook(`afterSanitizeAttributes`, function(node) {
// Force all links to open in new tab with security attributes
if (`tagName` in node && node.tagName === `A`) {
node.setAttribute(`target`, `_blank`);
node.setAttribute(`rel`, `noopener noreferrer nofollow`);
}
});

const sanitizedHtml = DOMPurify.sanitize(renderedHtml, {
ALLOWED_TAGS: [
// Basic
Expand All @@ -98,17 +113,29 @@ const MarkdownBody = (props: { markdown: string, }) => {
`mark`,
`ins`,
`small`,
`abbr`
`abbr`,
// Links (safe with DOMPurify's URL sanitization)
`a`
],
ALLOWED_ATTR: [
`title`,
`open`
`open`,
`class`,
`href`, // DOMPurify by default blocks dangerous protocols (javascript:, data:, vbscript:) and only allows safe ones (http:, https:, mailto:, etc.)
`target`,
`rel`
],
FORBID_TAGS: [`a`, `img`, `script`, `object`, `embed`, `iframe`, `link`],
FORBID_ATTR: [`href`, `src`, `class`, `id`, `style`, `target`],
ALLOW_DATA_ATTR: false
// Critical: Keep blocking dangerous tags that were part of the original vulnerability
FORBID_TAGS: [`img`, `script`, `object`, `embed`, `iframe`, `link`, `form`, `input`, `style`, `meta`, `base`],
FORBID_ATTR: [`src`, `id`, `style`, `onclick`, `onload`, `onerror`, `action`, `method`],
ALLOW_DATA_ATTR: false,
// Force secure link attributes
ADD_ATTR: [`target`, `rel`]
});

// Clean up the hook after sanitization to avoid memory leaks
DOMPurify.removeHook(`afterSanitizeAttributes`);

return (
<div
className="markdown-body"
Expand Down
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