Overview
CVE-2025-53739 is a critical vulnerability that affects Microsoft Office Excel. The vulnerability stems from an access of resource using incompatible type, otherwise known as ‘type confusion’. This flaw can be exploited by an unauthorized attacker to execute code locally on the victim’s system. Given the widespread use of Microsoft Office Excel in both professional and personal contexts, this vulnerability has far-reaching implications. If successfully exploited, it could potentially compromise systems or lead to data leakage, posing a significant threat to data privacy and system integrity.
Vulnerability Summary
CVE ID: CVE-2025-53739
Severity: High (7.8 CVSS Score)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: System compromise, potential 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
The CVE-2025-53739 vulnerability involves ‘type confusion’ in Microsoft Office Excel. Normally, different types of data in a program are handled using separate, compatible resources. However, a flaw in Excel allows an attacker to manipulate these data types in a way the program does not expect, causing confusion.
An attacker, for instance, could craft a malicious Excel file that causes the program to treat a string of text as if it were a pointer to a memory location. This could allow the attacker to execute arbitrary code on the victim’s system when the file is opened.
Conceptual Example Code
While the specifics of exploiting this vulnerability are complex and depend on the system’s exact configuration, a conceptual example might look something like this:
=A1+MALICIOUS_CODE()In this example, `A1` is a normal cell reference, but `MALICIOUS_CODE()` represents an attacker’s attempt to introduce an unexpected data type – executable code – into a calculation. When Excel tries to perform the operation, it may execute the attacker’s code, leading to potential system compromise or data leakage.
Note: This is a simplification for illustrative purposes. Actual exploitation would involve specific memory mapping techniques and carefully crafted code to exploit the type confusion flaw.
