CVE-2025-24078 is a high-severity use-after-free vulnerability identified in Microsoft Office 2019, specifically affecting the Word component. The vulnerability arises from improper handling of memory where a previously freed object is accessed, leading to undefined behavior. This flaw allows an unauthorized attacker to execute arbitrary code locally on the affected system. Exploitation requires the victim to open a specially crafted Word document, which triggers the use-after-free condition. The CVSS 3.1 base score is 7.0, indicating a high impact with the vector AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H, meaning the attack requires local access, high attack complexity, no privileges, and user interaction, but results in high confidentiality, integrity, and availability impacts. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk due to the widespread use of Microsoft Office 2019 in enterprise environments. The lack of an official patch at the time of publication increases the urgency for mitigation. The vulnerability is categorized under CWE-416 (Use After Free), a common memory corruption issue that can lead to arbitrary code execution, system crashes, or privilege escalation if exploited successfully.

For European organizations, the impact of CVE-2025-24078 could be substantial. Microsoft Office 2019 is widely deployed across various sectors including government, finance, healthcare, and critical infrastructure. Successful exploitation could lead to local code execution, enabling attackers to install malware, steal sensitive data, or disrupt operations. Given the high confidentiality, integrity, and availability impacts, this vulnerability could facilitate espionage, data breaches, or ransomware deployment. The requirement for local access and user interaction somewhat limits remote exploitation but does not eliminate risk, especially in environments where users frequently open documents from external or untrusted sources. The vulnerability could be leveraged in targeted attacks against high-value European entities, potentially impacting compliance with GDPR and other data protection regulations due to unauthorized data access or leakage.

European organizations should implement a multi-layered mitigation approach beyond generic advice: 1) Enforce strict email and document filtering policies to block or quarantine suspicious Word documents, especially those originating from external or untrusted sources. 2) Educate users about the risks of opening unsolicited or unexpected attachments and encourage verification of document sources. 3) Employ application control or sandboxing technologies to restrict execution of untrusted Office macros or embedded code. 4) Monitor endpoint behavior for signs of exploitation attempts, such as unusual memory access patterns or process anomalies related to Microsoft Word. 5) Prepare for rapid deployment of official patches once released by Microsoft by maintaining an up-to-date asset inventory and patch management process. 6) Consider disabling legacy or unnecessary Office features that could be exploited. 7) Use endpoint detection and response (EDR) solutions to detect and respond to exploitation attempts in real time. These targeted measures will reduce the attack surface and improve detection capabilities against exploitation of this use-after-free vulnerability.