CVE-2025-27751 in Excel
Summary
by MITRE • 04/08/2025
Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 07/07/2026
This vulnerability represents a critical use-after-free condition in Microsoft Office Excel that enables remote code execution through local privilege escalation. The flaw occurs when the application fails to properly validate memory references after objects have been freed, creating opportunities for attackers to manipulate memory contents and execute arbitrary code with the privileges of the targeted user. Such vulnerabilities typically arise from improper memory management practices where objects remain accessible in memory even after their destruction or deallocation. The technical implementation involves exploitation of heap corruption mechanisms that allow attackers to overwrite function pointers or control structures within the application's memory space, ultimately leading to code execution. This type of vulnerability falls under the common weakness enumeration CWE-416 which specifically addresses use-after-free conditions in software applications.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with persistent access to target systems through Microsoft Office Excel's widespread deployment across enterprise environments. Since Excel is frequently used for document processing and spreadsheet analysis, attackers can leverage this vulnerability through malicious spreadsheets delivered via email attachments or compromised websites. The attack vector typically involves crafting specially formatted excel files that trigger the memory corruption when opened by vulnerable applications. This approach aligns with ATT&CK technique T1059.005 for command and scripting interpreter execution through office applications, representing a common initial access method in enterprise security breaches.
Mitigation strategies should focus on immediate patch management and application hardening measures to prevent exploitation of this vulnerability. Microsoft has released security updates that address the memory corruption issues within Excel's object handling mechanisms, requiring administrators to deploy these patches across all affected systems immediately. Additional protective measures include implementing application whitelisting policies that restrict execution of unauthorized Office macros, enabling protected view mode for documents from untrusted sources, and configuring user access controls that limit file execution privileges. Network-based protections such as email filtering solutions can help block malicious attachments while endpoint detection and response tools should monitor for suspicious process creation patterns associated with exploitation attempts. Organizations should also consider implementing macro security policies that disable or restrict ActiveX controls and embedded scripts within Office documents to minimize attack surface exposure. The vulnerability demonstrates the critical importance of maintaining up-to-date software versions and implementing layered defense mechanisms to protect against sophisticated exploitation techniques targeting common enterprise applications.