CVE-2025-47167: Microsoft Office Type Confusion Vulnerability Leading to Unauthorized Local Code Execution

Overview

In this article, we will delve into the details of a severe vulnerability that affects Microsoft Office, one of the world’s most widely used office productivity software suites. The vulnerability, identified as CVE-2025-47167, involves a type confusion flaw that could potentially allow an unauthorized attacker to execute code locally on a victim’s system.
This vulnerability matters because of the ubiquitous nature of Microsoft Office. With millions of users worldwide, both in personal and professional settings, a vulnerability of this nature could potentially lead to substantial data breaches and unauthorized system access. This underscores the need for rigorous cybersecurity measures and the importance of staying informed about the latest vulnerabilities and their mitigation strategies.

Vulnerability Summary

CVE ID: CVE-2025-47167
Severity: High (CVSS: 8.4)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: Unauthorized local code execution leading to potential system compromise or data leakage

Affected Products

Product | Affected Versions

Microsoft Office | All Versions Up To Latest Patch

How the Exploit Works

The vulnerability originates from a type confusion flaw in Microsoft Office. An attacker can craft a malicious Microsoft Office document that abuses this flaw, effectively tricking the software into treating one type of data as if it were a different type. Once the document is opened by a user, the attacker’s code is executed locally on the user’s system.

Conceptual Example Code

Here is a conceptual example of how an attacker might exploit this vulnerability. It involves crafting a malicious payload within a Microsoft Word document.

Open New Microsoft Word Document
Embed Payload {
Type: 'Expected Data Type',
Content: 'Malicious Code'
}
Save Document as 'Compromised.docx'
Send 'Compromised.docx' to Target

In this pseudocode, the attacker creates a new Word document, embeds the malicious code within it (while presenting it as an expected data type), and then saves and sends the document to the target. When the target opens the document, the malicious code is executed.

Mitigation

The primary solution to this vulnerability is to apply the latest patches provided by Microsoft. Regularly updating your software ensures that you are protected against known vulnerabilities. For immediate, temporary mitigation, users can use a Web Application Firewall (WAF) or an Intrusion Detection System (IDS). These systems can detect and block attempts to exploit this vulnerability. However, these are not long-term solutions and should not replace the application of the vendor-provided patch.
Remember that in cybersecurity, staying updated is one of the most effective ways to protect your systems and data from threats.