CVE-2025-47169: Heap-based Buffer Overflow Vulnerability in Microsoft Office Word

Overview

A new vulnerability, CVE-2025-47169, has been identified in Microsoft Office Word that is of serious concern to any organization or individual using the software. This vulnerability can allow unauthorized attackers to execute code locally on the victim’s machine, potentially leading to system compromise or data leakage. Given the pervasive use of Microsoft Word across various sectors, the impact of this vulnerability could be widespread if not properly addressed.

Vulnerability Summary

CVE ID: CVE-2025-47169
Severity: High (7.8/10)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: System compromise or data leakage

Affected Products

Product | Affected Versions

Microsoft Office Word | All versions before patch

How the Exploit Works

The exploit takes advantage of a heap-based buffer overflow vulnerability in Microsoft Office Word. An attacker sends a specially crafted Word document to the victim. When the victim opens this document, the buffer overflow is triggered. This causes data to be written beyond the buffer’s boundary, leading to arbitrary code execution in the context of the current user.

Conceptual Example Code

The actual exploit would require a sophisticated understanding of buffer overflows and intricate knowledge of Word’s internal workings. However, a conceptual version can be represented as follows:

class BufferOverflow:
def __init__(self, buffer_size):
self.buffer = [None]*buffer_size
def overflow(self, data, index):
self.buffer[index] = data
# Attacker creates buffer overflow object
exploit = BufferOverflow(10)
# Attacker overflows buffer with malicious code
for i in range(20):
exploit.overflow("malicious code", i)

In this conceptual example, the BufferOverflow class represents a buffer in Word. The attacker is able to overflow the buffer by writing more data to it than it can hold.

Mitigation Guidance

Microsoft has released a patch to address this vulnerability. Users are strongly advised to apply this patch immediately to protect against potential attacks. Until the patch can be applied, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used as temporary mitigation. These tools can help to identify and block attempts to exploit the vulnerability.
It’s essential to remain vigilant and ensure that all software, especially widely-used ones like Microsoft Word, are regularly updated to the most recent versions to stay protected against such vulnerabilities.