Overview
The cybersecurity world is witnessing a new vulnerability that affects Microsoft Office Excel. Identified as CVE-2025-53741, this vulnerability is a heap-based buffer overflow that allows an unauthorized attacker to execute code locally. Given the wide usage of Excel across organizations worldwide, this vulnerability poses a significant risk. Buffer overflow vulnerabilities are not new, but their impact can be severe due to the potential for system compromise or data leakage.
Vulnerability Summary
CVE ID: CVE-2025-53741
Severity: High (CVSS 7.8)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: System compromise or data leakage
Affected Products
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Product | Affected Versions
Microsoft Office Excel | All versions prior to the latest patch
How the Exploit Works
A heap-based buffer overflow is a type of vulnerability which occurs when data written to a buffer exceeds its capacity, and overflows onto the adjacent memory, causing it to overwrite other data. In the case of CVE-2025-53741, an attacker can exploit Excel’s failure to properly allocate and monitor the size of objects or data in memory. By sending a specially crafted file to the victim and tricking them into opening it with Excel, the attacker can execute arbitrary code in the context of the current user.
Conceptual Example Code
Here is a conceptual example of how this vulnerability might be exploited. This is not actual code but an illustrative scenario to show how an attacker might take advantage of the buffer overflow:
# An attacker creates a specially crafted Excel file with oversized cells
malicious_file = create_excel_file_with_oversized_cells()
# This file is then sent to the victim, who opens it with Excel
open_excel_file(malicious_file)
# The oversized cells cause a buffer overflow, allowing the attacker to execute code
execute_code(malicious_file)Mitigation Guidance
It is strongly recommended that users and administrators apply the vendor patch as soon as possible. In the absence of a patch, a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as temporary mitigation. However, these measures can only detect and possibly block known exploits and may not protect against new or unknown ones. Therefore, applying the vendor patch remains the most effective solution to this vulnerability.
