CVE-2025-29978: Use After Free Vulnerability in Microsoft Office PowerPoint Allowing Unauthorized Local Code Execution

Overview

In this blog post, we will be diving deep into a recently identified vulnerability tagged as CVE-2025-29978. This critical vulnerability resides in Microsoft Office’s PowerPoint software and can potentially allow an unauthorized attacker to execute code locally on the victim’s machine. The widespread usage of Microsoft Office makes this a high-risk vulnerability that can potentially affect millions of users, underlining its significance in the cybersecurity realm.

Vulnerability Summary

CVE ID: CVE-2025-29978
Severity: High (7.8 CVSS Score)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: Can lead to system compromise and potential data leakage

Affected Products

Product | Affected Versions

Microsoft Office PowerPoint | All versions till patch released

How the Exploit Works

This flaw is a ‘use after free’ vulnerability. This type of vulnerability surfaces when a program continues to use a pointer after it has been freed. In the context of CVE-2025-29978, an attacker could craft a malicious PowerPoint file that, when opened, triggers the vulnerability, allowing the attacker to execute code on the victim’s machine. This code could be used to compromise the system or extract sensitive data.

Conceptual Example Code

While it’s not feasible to provide exact exploit code, the following pseudocode provides a conceptual overview of what an attack might look like:

def exploit(target_file):
# Create a malicious object
malicious_object = create_malicious_object()
# Open the target PowerPoint file
ppt_file = open(target_file, 'r+b')
# Embed the malicious object into the PowerPoint file
embed_object(ppt_file, malicious_object)
# Save the modified file
ppt_file.save(target_file)
# The malicious PowerPoint file is now set to exploit the vulnerability when opened

This pseudocode is a simplified representation of an exploit. The actual exploit would be more complex and would depend on the specific details of the vulnerability.

Mitigation and Prevention

At the time of writing this post, Microsoft has released a patch to address this vulnerability. Users are urged to apply this patch as soon as possible to ensure their systems are secure. In cases where immediate patching is not feasible, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can offer temporary mitigation. However, these are not foolproof solutions and patching should be the ultimate goal.
Remember, staying updated on the latest patches and practicing good cybersecurity hygiene are your best defences against potential threats.