In the world of software security, vulnerabilities are found and patched all the time. Not all of them are equally dangerous, but vulnerabilities that allow privilege escalation are always serious. One such security flaw, CVE-2022-30127, was revealed in Microsoft's Chromium-based Edge browser. This post will explore what CVE-2022-30127 is, how it works, show some example code, and share useful links for anyone who needs to dive deeper.

> Note: CVE-2022-30127 is different from CVE-2022-30128. Each CVE ID describes a unique security flaw.

What is CVE-2022-30127?

CVE-2022-30127 is an *elevation of privilege* vulnerability found in Microsoft Edge (based on Chromium). It means that a user with limited permissions could exploit this issue to run code or perform tasks with higher privileges than intended.

In simpler terms:
Attackers could use this flaw to gain more access on your computer — potentially taking over functions only administrators should have.

How Does The Vulnerability Work?

While Microsoft did not publish full technical details (to protect users until everyone patches), here's the general idea:

- A flaw in Edge's Chromium base allows a user (or malicious script) to break out of the standard, restricted sandbox.
- Under specific conditions, code running in the browser could trick the system into granting higher permissions.

Sample Code Snippet (Proof-of-Concept)

Disclaimer:
This is a *conceptual* demonstration. Actual working exploit code was not made public. This snippet shows how an attacker might try to escape sandbox restrictions by abusing privileged browser APIs.

// Conceptual Example: Trying to access files outside the allowed sandbox
try {
    let fs = require('fs');
    // Attempt to read a protected system file (e.g., Windows hosts file)
    let data = fs.readFileSync('C:\\Windows\\System32\\drivers\\etc\\hosts', 'utf8');
    console.log(data);
} catch (e) {
    // In a secure browser, this should fail
    console.error("Access denied:", e.message);
}

*Normally, this JavaScript code should not work in the browser, as require isn't allowed and file system access is blocked. A bug that allows this kind of code would be serious!*

Why is This Vulnerable?

When browsers execute code, they use a "sandbox" — a protective barrier to keep web content away from your system files and passwords. If a bug in the Chromium engine lets code bypass the sandbox, attackers can reach parts of your computer that should be off-limits.

Exploitation Details

Microsoft marked this as "Important" on their Security Update Guide.

- Attack Vector: Usually requires visiting a specially crafted website or clicking a malicious link.
- Privileges required: Low. Attackers don't need to trick the user into installing anything, just visiting a web page.
- Impact: Attackers could execute code with higher privileges, potentially taking over the affected account.

The attack abuses higher permissions to alter files or run harmful commands.

This vulnerability does not require prior authentication but does depend on users being tricked into viewing malicious web pages.

Mitigation & Patch

The best defense is to update Edge to the latest version. Microsoft worked with the Chromium team to quickly patch this flaw in both Edge and upstream Chromium projects. Older, unpatched versions are still at risk.

How to update Edge:

Open Edge → settings → About Microsoft Edge. The browser will check and install updates automatically.

- Microsoft Security Update Guide – CVE-2022-30127
- Microsoft Edge Security Updates
- CVE Details for CVE-2022-30127 (cvedetails.com)
- Chromium Security Page

Conclusion

Security vulnerabilities like CVE-2022-30127 show why it’s so important to keep your browser up to date. Even trusted software can have dangerous flaws that cybercriminals are ready to exploit. Always update promptly, be careful about the links you click, and never run browsers on privileged accounts unless absolutely necessary.

Timeline

Published on: 06/01/2022 20:15:00 UTC
Last modified on: 08/15/2022 11:21:00 UTC