CVE-2024-30101 is a use-after-free vulnerability (CWE-416) identified in Microsoft 365 Apps for Enterprise, specifically affecting version 16.0.1. This vulnerability arises when the application improperly manages memory, freeing an object while it is still in use, which can lead to arbitrary code execution. An attacker can exploit this flaw by convincing a user to open a maliciously crafted Office document, triggering the vulnerability. The attack vector is network-based (AV:N), but it requires user interaction (UI:R) and has a high attack complexity (AC:H), meaning the attacker must craft a precise exploit and rely on user action. No privileges or authentication are required (PR:N). Successful exploitation can compromise confidentiality, integrity, and availability of the affected system, allowing remote code execution under the context of the current user. The vulnerability has a CVSS 3.1 base score of 7.5, reflecting its high severity. Although no known exploits have been reported in the wild yet, the widespread deployment of Microsoft 365 in enterprise environments makes this a critical issue. The vulnerability was publicly disclosed on June 11, 2024, and is currently in a published state with no official patch links provided yet. The vulnerability is enriched by CISA, indicating its recognition as a significant security concern.

European organizations face substantial risks from this vulnerability due to the extensive use of Microsoft 365 Apps for Enterprise across public and private sectors. Exploitation could lead to unauthorized remote code execution, enabling attackers to steal sensitive data, disrupt business operations, or deploy ransomware and other malware. The impact is particularly severe for industries handling critical infrastructure, government agencies, financial institutions, and healthcare providers, where confidentiality and availability are paramount. The requirement for user interaction means phishing or social engineering campaigns could be leveraged to trigger the exploit. Given the high integration of Microsoft 365 in European workplaces, a successful attack could propagate rapidly, affecting multiple systems and causing widespread operational disruption and data breaches.

Organizations should implement a multi-layered defense strategy. First, monitor Microsoft’s official channels closely for patches and apply them immediately upon release. Until patches are available, restrict the opening of Office documents from untrusted or unknown sources, and disable macros and embedded content by default. Employ advanced email filtering and phishing detection to reduce the risk of malicious document delivery. Enhance endpoint detection and response (EDR) capabilities to identify suspicious behaviors indicative of exploitation attempts. Conduct user awareness training focused on recognizing phishing and social engineering tactics. Network segmentation can limit lateral movement if an endpoint is compromised. Additionally, enforce the principle of least privilege to minimize the impact of a successful exploit. Regularly back up critical data and verify recovery procedures to mitigate ransomware risks stemming from this vulnerability.