CVE-2025-27747 in Word
Summary
by MITRE • 04/08/2025
Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 05/19/2026
This vulnerability represents a critical use-after-free flaw in Microsoft Office Word that enables remote code execution through maliciously crafted documents. The vulnerability occurs when the application fails to properly validate memory management during document processing, specifically when handling certain object references after they have been freed from memory. This type of vulnerability falls under the CWE-416 category of Use After Free conditions where memory is accessed after it has been deallocated, creating a potential exploitation vector for attackers to execute arbitrary code with the privileges of the targeted user. The flaw exists in the document parsing and rendering components of Word, particularly when processing specific file formats or embedded objects that trigger improper memory handling.
The operational impact of this vulnerability extends beyond simple code execution as it provides attackers with a persistent foothold for further exploitation within the victim environment. An attacker could craft a malicious Word document containing specially formatted content that, when opened by an unpatched victim, triggers the use-after-free condition. This could lead to privilege escalation, data exfiltration, or deployment of additional malware payloads. The vulnerability is particularly dangerous because it requires no user interaction beyond opening the document, making it a prime candidate for phishing campaigns or drive-by downloads. Security researchers have identified this issue as a high-severity threat that aligns with ATT&CK technique T1059.005 for command and scripting interpreter, where the initial code execution can be leveraged for further system compromise.
Mitigation strategies should focus on immediate patch management and operational security measures to protect against exploitation. Microsoft has released security updates addressing this vulnerability through regular security patches, and organizations should prioritize deployment of these updates across all affected systems. Network segmentation and email filtering can help reduce the attack surface by limiting document delivery vectors and preventing initial access. Additional protective measures include implementing application whitelisting policies, disabling macro execution in Word, and conducting regular security assessments to identify potential exploitation attempts. The vulnerability demonstrates the importance of proper memory management practices in software development and highlights the critical need for thorough security testing of document processing components. Organizations should also consider implementing endpoint detection and response solutions to monitor for suspicious memory access patterns that could indicate exploitation attempts, as these tools can provide early warning of potential attacks leveraging use-after-free conditions.