CVE-2025-49713: Microsoft Edge Type Confusion Vulnerability Permitting Unauthorized Code Execution

Overview

CVE-2025-49713 is a critical vulnerability discovered in the Chromium-based Microsoft Edge browser, which has significant security implications. This flaw allows an unauthorized attacker to execute arbitrary code over a network, potentially leading to a total compromise of the system or potential data leakage. This vulnerability is particularly crucial as Microsoft Edge is one of the widely used browsers, hence affecting a large population of users. The severity of this vulnerability is emphasized by its CVSS Severity Score of 8.8, indicating a high level of risk.

Vulnerability Summary

CVE ID: CVE-2025-49713
Severity: High (8.8 CVSS Score)
Attack Vector: Network
Privileges Required: None
User Interaction: Required
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

Microsoft Edge (Chromium-based) | All versions prior to the issuance of the patch

How the Exploit Works

This vulnerability revolves around a type confusion flaw. Type confusion, also known as type mismatch or type discrepancy, is an error that occurs when a code entity is accessed as if it were a different type. In the context of this vulnerability, the Chromium-based Microsoft Edge incorrectly handles memory objects. A successful exploit could allow an attacker to execute arbitrary code in the context of the current user. If the current user is logged in with administrative rights, an attacker could take control of an affected system.

Conceptual Example Code

Here’s a conceptual example of how an attacker might exploit this vulnerability. This pseudocode is purposefully incomplete and non-functional to prevent misuse:

// JavaScript pseudocode
let obj = {a: 1};
let arr = [1.1, 2.2, 3.3];
// Trigger type confusion
let confusedType = arr.map(function(x) {
if(typeof x === 'object') {
return obj;
}
return x;
});
// Use confused type to execute malicious payload
confusedType[10] = execute_malicious_payload();

In this pseudocode, an attacker triggers the type confusion by mapping an array (arr) to an object (obj). The attacker then exploits this type confusion to execute malicious code.

Prevention and Mitigation

Microsoft has provided a patch to address this vulnerability. Users are strongly urged to update their Microsoft Edge browsers to the latest version. For those unable to patch immediately, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation, although this is not a replacement for patching the vulnerability at the earliest convenience.