CVE-2025-29823 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 • 07/13/2026
This vulnerability represents a critical use-after-free condition in Microsoft Office Excel that enables remote code execution through maliciously crafted spreadsheet files. The flaw occurs when the application fails to properly manage memory references after objects have been freed, creating opportunities for attackers to manipulate memory layout and execute arbitrary code with the privileges of the targeted user. Such vulnerabilities typically arise from insufficient validation of object lifecycles within the application's memory management subsystem, allowing attackers to overwrite freed memory regions with malicious payloads.
The technical exploitation involves crafting Excel files containing specially designed objects that trigger the use-after-free condition during normal spreadsheet processing operations. When Excel attempts to access the freed memory location, it may redirect execution flow to attacker-controlled code embedded within the malicious file structure. This vulnerability primarily affects Microsoft Office installations running on windows operating systems and can be triggered through various attack vectors including email attachments, web downloads, or malicious documents shared through collaboration platforms.
From an operational perspective this vulnerability poses significant risks to enterprise environments where users frequently interact with spreadsheet files from untrusted sources. The attack surface expands considerably as users may inadvertently open malicious files while performing routine tasks such as document review, data analysis, or collaboration activities. Organizations face potential compromise of sensitive corporate data, lateral movement within network environments, and establishment of persistent backdoors through this code execution vector.
Mitigation strategies should focus on immediate patch management implementation for affected Microsoft Office versions and deployment of additional security layers including email filtering solutions, application whitelisting policies, and network-based intrusion detection systems. Organizations should also implement user awareness training to reduce the likelihood of accidental exploitation through social engineering attacks targeting spreadsheet file attachments. The vulnerability aligns with CWE-416 which addresses use-after-free conditions in software applications and represents a common target for attackers leveraging the ATT&CK technique T1059.001 for command and control operations. Regular security assessments and monitoring of anomalous Excel process behaviors can help detect exploitation attempts before full compromise occurs, while maintaining up-to-date threat intelligence feeds provides early warning capabilities against emerging attack patterns targeting this specific vulnerability class.