CVE-2025-47174: Heap-Based Buffer Overflow in Microsoft Office Excel Leading to Unauthorized Code Execution

Overview

The cybersecurity landscape is constantly evolving with new threats emerging on a regular basis. One such threat that has come to light recently is the CVE-2025-47174 vulnerability. This vulnerability is a heap-based buffer overflow in Microsoft Office Excel. This vulnerability is of significant concern as it allows an unauthorized attacker to execute code locally. It affects any individual or organization that utilizes Microsoft Office Excel, emphasizing the importance of taking prompt action to address this security risk.

Vulnerability Summary

CVE ID: CVE-2025-47174
Severity: High (CVSS 7.8)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

Microsoft Office Excel | All versions prior to patch

How the Exploit Works

This exploit takes advantage of a heap-based buffer overflow in Microsoft Office Excel. A buffer overflow occurs when a program or process attempts to write more data to a fixed-length block of memory, or buffer, than it can hold. In this case, the overflow is happening in the heap, a region of a computer’s memory space that is used for dynamic memory allocation. An attacker can manipulate this vulnerability to execute arbitrary code on the system running the vulnerable software.

Conceptual Example Code

While we do not provide actual exploit code, the following conceptual example illustrates how an attacker might use a crafted Excel spreadsheet to exploit this vulnerability:

# Hypothetical Python-based exploit
import malicious_module
def create_exploit():
buffer = "A" * 5000  # Overflow the buffer
malicious_code = malicious_module.generate_code()  # Generate malicious code
spreadsheet = open("exploit.xls", "w")
spreadsheet.write(buffer + malicious_code)
spreadsheet.close()
create_exploit()

In this conceptual example, the attacker creates an Excel spreadsheet with a large amount of data (“A” * 5000) to overflow the buffer. They then append malicious code to this overflowed buffer and save it within an Excel file (`exploit.xls`). When this file is opened in a vulnerable version of Excel, the overflow occurs, executing the malicious code.