| Package | Affected versions | Patched versions |
|---|---|---|
| mermaid | ≥ 11.1.0, < 11.10.0 | 11.10.0 |
| mermaid | ≥ 11.1.0, < 11.10.0 | 11.10.0 |
In the default configuration of mermaid 11.9.0, user supplied input for architecture diagram icons is passed to the d3 html() method, creating a sink for cross site scripting.
Architecture diagram service iconText values are passed to the d3 html() method, allowing malicious users to inject arbitrary HTML and cause XSS when mermaid-js is used in it's default configuration.
The vulnerability lies here:
export const drawServices = async function (
db: ArchitectureDB,
elem: D3Element,
services: ArchitectureService[]
): Promise<number> {
for (const service of services) {
/** ... **/
} else if (service.iconText) {
bkgElem.html(
`<g>${await getIconSVG('blank', { height: iconSize, width: iconSize, fallbackPrefix: architectureIcons.prefix })}</g>`
);
const textElemContainer = bkgElem.append('g');
const fo = textElemContainer
.append('foreignObject')
.attr('width', iconSize)
.attr('height', iconSize);
const divElem = fo
.append('div')
.attr('class', 'node-icon-text')
.attr('style', `height: ${iconSize}px;`)
.append('div')
.html(service.iconText); // <- iconText passed into innerHTML
/** ... **/
};
};
This issue was introduced with 734bde38777c9190a5a72e96421c83424442d4e4, around 15 months ago, which was released in v11.1.0.
Render the following diagram and observe the modified DOM.
architecture-beta
group api(cloud)[API]
service db "<img src=x onerror=\"document.write(`xss on ${document.domain}`)\">" [Database] in api
XSS on all sites that use mermaid and render user supplied diagrams without further sanitization.
Sanitize the value of iconText before passing it to html().
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