Introduction
Microsoft Excel, a cornerstone of enterprise productivity, faces yet another critical security challenge with CVE-2025-30379. This vulnerability, rooted in improper memory handling, allows attackers to execute arbitrary code locally, posing significant risks to data integrity and system security.
Affected Systems and Versions
The vulnerability specifically impacts the following Microsoft Excel versions:
- Microsoft Excel 2016
- Microsoft Excel 2019
- Microsoft Excel 2021
- Microsoft Excel 2024
- Microsoft 365 Apps
All configurations of these versions are vulnerable when handling maliciously crafted Excel files.
Technical Information
CVE-2025-30379 stems from Excel's improper handling of memory pointers, classified under CWE-763 (Release of Invalid Pointer or Reference). When a user opens a specially crafted Excel file, the application incorrectly releases memory resources, causing memory corruption. This corruption can be leveraged by attackers to execute arbitrary code at the user's privilege level.
The attack vector requires local access and user interaction, typically delivered via phishing emails containing malicious Excel attachments. Upon opening the file, the invalid pointer release triggers memory corruption, allowing attackers to execute arbitrary code.
Patch Information
Microsoft has addressed this vulnerability in its May 2025 security update (KB5002695). Users should immediately apply this update to the affected Excel versions. The patch is available through Microsoft's standard update channels:
Additional mitigation measures include enforcing strict user permissions, network segmentation, and user training to recognize and avoid malicious files.
Detection Methods
Organizations can detect potential exploitation attempts by monitoring for abnormal Excel process behavior, particularly unexpected memory usage or crashes. Endpoint Detection and Response (EDR) solutions can help identify suspicious Excel activities. Currently, there are no known indicators of compromise or specific log patterns associated with this vulnerability.
Vendor Security History
Microsoft has historically faced numerous vulnerabilities related to memory management in its Office suite, particularly Excel. Similar vulnerabilities, such as CVE-2025-30393, highlight ongoing challenges in securing complex software. Microsoft's structured monthly patching approach demonstrates proactive security management, yet legacy codebases continue to present persistent vulnerabilities.
