CVE-2025-47957 is a high-severity use-after-free vulnerability (CWE-416) found in Microsoft 365 Apps for Enterprise, specifically affecting Microsoft Office Word version 16.0.1. This vulnerability allows an unauthorized attacker to execute arbitrary code locally on a victim's machine without requiring user interaction or prior authentication. The flaw arises from improper handling of memory in Word, where a previously freed memory object is accessed, leading to undefined behavior that can be exploited to execute malicious code. The CVSS v3.1 base score is 8.4, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges or user interaction needed. Although no known exploits are currently in the wild, the vulnerability's characteristics make it a significant risk, especially in environments where Microsoft 365 Apps for Enterprise is widely deployed. The vulnerability is publicly disclosed and assigned a CVE identifier, but as of now, no official patches have been released. The lack of patch availability increases the urgency for organizations to implement interim mitigations and monitor for potential exploit attempts.

For European organizations, this vulnerability poses a substantial threat given the widespread use of Microsoft 365 Apps for Enterprise across enterprises, government agencies, and critical infrastructure sectors. Successful exploitation could lead to local code execution, enabling attackers to gain control over affected systems, steal sensitive data, disrupt operations, or move laterally within networks. The high impact on confidentiality, integrity, and availability means that data breaches, ransomware deployment, or sabotage are plausible outcomes. Sectors such as finance, healthcare, public administration, and manufacturing, which heavily rely on Microsoft Office tools, are particularly at risk. The vulnerability's ability to be exploited without user interaction or privileges further exacerbates the threat, potentially allowing automated or wormable attacks within corporate networks. This could lead to significant operational disruptions and financial losses, as well as reputational damage for affected organizations.

Given the absence of an official patch, European organizations should implement the following specific mitigations: 1) Restrict execution of untrusted or unsolicited Word documents by enforcing strict email filtering and attachment scanning policies. 2) Employ application whitelisting and sandboxing techniques to limit the execution context of Microsoft Word processes. 3) Enable and enforce enhanced memory protection features such as Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR) on endpoints. 4) Monitor endpoint behavior for anomalous activities indicative of exploitation attempts, including unusual process spawning or memory access patterns. 5) Educate users about the risks of opening unexpected or suspicious Word documents, even though user interaction is not required for exploitation, as social engineering remains a common attack vector. 6) Prepare for rapid deployment of patches once released by Microsoft by maintaining an up-to-date asset inventory and patch management process. 7) Consider network segmentation to limit lateral movement if an endpoint is compromised. These measures, combined, can reduce the attack surface and limit potential damage until a patch is available.