Overview

The CVE-2025-9180 is a high-risk vulnerability scored at 8.1 on the CVSS scale, which is found in the Graphics: Canvas2D component of Mozilla Firefox and Thunderbird. It enables an attacker to bypass the same-origin policy, a critical security component that restricts how a document or script loaded from one origin can interact with a resource from another origin. This vulnerability can lead to potential system compromise or data leakage, posing a significant threat to user data and system integrity.
It’s not just a concern for individual users, but also for organizations that rely on these popular web browsers and email clients for their daily operations. Understanding the implications of this vulnerability and applying appropriate mitigations is crucial to maintain secure online environments.

Vulnerability Summary

CVE ID: CVE-2025-9180
Severity: High (CVSS: 8.1)
Attack Vector: Network
Privileges Required: None
User Interaction: Required
Impact: Potential System Compromise and Data Leakage

Affected Products

Product | Affected Versions

Firefox | < 142 Firefox ESR | < 115.27, < 128.14, < 140.2 Thunderbird | < 142, < 128.14, < 140.2 How the Exploit Works

This exploit takes advantage of a flaw in the Graphics: Canvas2D component that fails to properly enforce the same-origin policy. The same-origin policy is a crucial security concept that prevents scripts on one web page from accessing data on another web page unless both pages have the same origin.
However, with CVE-2025-9180, an attacker can craft a malicious script that bypasses this policy and accesses data from different origins. This could allow an attacker to steal sensitive user data from other web pages or even perform actions on behalf of the user without their knowledge or consent.

Conceptual Example Code

Below is a conceptual example of how this vulnerability might be exploited. An attacker might craft a malicious JavaScript code that targets the Canvas2D component to bypass the same-origin policy.

var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
var img = new Image();
img.crossOrigin = 'Anonymous';
img.onload = function() {
ctx.drawImage(img, 0, 0);
var data = ctx.getImageData(0, 0, img.width, img.height);
// send data to attacker's server
}
img.src = 'http://target-site.com/private-image.jpg';
document.body.appendChild(canvas);

In this example, the attacker creates an image element and sets its `crossOrigin` attribute to `’Anonymous’` to bypass the same-origin policy. They then draw the image onto a canvas and extract its data, which could include sensitive information that they can send to their own server. This code could be delivered to a victim’s browser through a range of methods, such as cross-site scripting (XSS) attacks or malicious advertisements.