CVE-2025-27749 is a high-severity use-after-free vulnerability identified in Microsoft Office 2019 (version 19.0.0). The vulnerability is categorized under CWE-416, which involves the improper handling of memory that has already been freed, leading to potential exploitation. Specifically, this flaw allows an unauthorized attacker to execute arbitrary code locally on a vulnerable system. The vulnerability requires local access (Attack Vector: Local) and low attack complexity, meaning an attacker with local access but no privileges can exploit it, though user interaction is required (UI:R). The vulnerability impacts confidentiality, integrity, and availability, all rated high, indicating that successful exploitation could lead to full system compromise, including data theft, system manipulation, or denial of service. The scope is unchanged, meaning the exploit affects only the vulnerable component without extending to other system components. No known exploits are currently reported in the wild, and no patches have been linked yet, though the vulnerability was published on April 8, 2025, with the reservation date on March 6, 2025. The CVSS vector indicates that no privileges are required (PR:N), but user interaction is necessary, such as opening a malicious document. This vulnerability is critical for environments where Microsoft Office 2019 is widely used, as it could be leveraged by attackers to gain code execution capabilities on targeted machines, potentially leading to lateral movement or persistence within networks.

For European organizations, the impact of CVE-2025-27749 could be significant due to the widespread use of Microsoft Office 2019 in corporate, governmental, and educational sectors. Exploitation could lead to unauthorized code execution, allowing attackers to steal sensitive data, deploy ransomware, or disrupt business operations. Given the local attack vector and requirement for user interaction, phishing campaigns or malicious document distribution remain likely attack vectors. The high impact on confidentiality, integrity, and availability means that critical data and systems could be compromised, leading to financial losses, reputational damage, and regulatory penalties under GDPR. Organizations with less mature endpoint protection or user awareness programs are particularly at risk. Additionally, sectors with high-value intellectual property or critical infrastructure, such as finance, healthcare, and government agencies, could face targeted attacks leveraging this vulnerability to gain footholds in their networks.

To mitigate this vulnerability effectively, European organizations should: 1) Prioritize patch management by monitoring Microsoft’s official channels for the release of security updates addressing CVE-2025-27749 and deploy them promptly. 2) Implement application whitelisting and restrict execution of unauthorized scripts or macros within Office documents to reduce the risk of malicious code execution. 3) Enhance endpoint detection and response (EDR) capabilities to identify suspicious behaviors indicative of use-after-free exploitation attempts. 4) Conduct targeted user awareness training focusing on the risks of opening unsolicited or unexpected Office documents, emphasizing the importance of verifying document sources. 5) Employ network segmentation to limit the lateral movement potential if a local compromise occurs. 6) Utilize advanced email filtering and sandboxing solutions to detect and block malicious attachments before reaching end users. 7) Regularly audit and harden local user privileges to minimize the impact of local code execution exploits.