CVE-2025-24079 is a high-severity use-after-free vulnerability identified in Microsoft Office Word 2019 (version 19.0.0). The vulnerability stems from improper memory management within the Word application, where a previously freed memory object is accessed again, leading to undefined behavior. This flaw can be exploited by an unauthorized attacker to execute arbitrary code locally on the affected system. The attack vector requires local access (AV:L), no privileges (PR:N), but user interaction (UI:R) is necessary, such as opening a specially crafted malicious Word document. The vulnerability impacts confidentiality, integrity, and availability, as successful exploitation allows full code execution with the privileges of the user running Word. The CVSS v3.1 base score is 7.8, reflecting high severity with high impact on confidentiality, integrity, and availability. No known exploits are currently reported in the wild, and no patches have been released yet. The vulnerability was reserved in January 2025 and published in March 2025, indicating recent discovery. The CWE classification is CWE-416 (Use After Free), a common memory corruption issue leading to potential arbitrary code execution. Since the vulnerability requires local access and user interaction, exploitation is somewhat limited to scenarios where an attacker can convince a user to open a malicious document or has local access to the machine. However, given the widespread use of Microsoft Office 2019 in enterprise environments, this vulnerability poses a significant risk if weaponized. The lack of an available patch necessitates immediate mitigation strategies to reduce exposure until an official fix is released.

For European organizations, the impact of CVE-2025-24079 can be substantial due to the extensive use of Microsoft Office 2019 across public and private sectors. Successful exploitation could lead to unauthorized code execution, enabling attackers to deploy malware, steal sensitive data, or disrupt business operations. Confidentiality breaches could expose personal data protected under GDPR, leading to regulatory penalties and reputational damage. Integrity and availability impacts could result in corrupted documents, loss of productivity, or ransomware deployment. The requirement for local access and user interaction somewhat limits remote exploitation but does not eliminate risk, especially in environments where phishing or social engineering attacks are common. Organizations with high reliance on Office documents for daily operations, such as financial institutions, government agencies, and critical infrastructure providers, face elevated risks. The absence of known exploits in the wild provides a window for proactive defense, but the high severity score underscores the urgency of addressing this vulnerability promptly.

1. Implement strict email filtering and attachment scanning to reduce the likelihood of malicious Word documents reaching end users. 2. Educate users on the risks of opening unsolicited or suspicious Office documents, emphasizing caution with email attachments and links. 3. Employ application whitelisting and sandboxing techniques to limit the execution scope of Office applications and isolate untrusted documents. 4. Use endpoint detection and response (EDR) tools to monitor for anomalous behavior indicative of exploitation attempts, such as unexpected process spawning or memory manipulation. 5. Restrict local access permissions and enforce the principle of least privilege to minimize the impact of local exploitation. 6. Regularly back up critical data and verify restoration procedures to mitigate potential data loss from exploitation. 7. Monitor vendor communications closely for the release of official patches and apply them immediately upon availability. 8. Consider deploying Microsoft Office Protected View and disabling macros by default to reduce attack surface. These measures, combined, provide layered defense until a patch is available.