CVE-2024-30104 is a vulnerability classified under CWE-59, which pertains to improper link resolution before file access, also known as 'link following.' This vulnerability affects Microsoft Office 2019, specifically version 19.0.0. The flaw arises when Office improperly resolves symbolic links or shortcuts before accessing files, allowing an attacker to manipulate the file path resolution process. By crafting a malicious Office document containing specially designed links, an attacker can cause Office to access unintended files or locations, potentially leading to remote code execution (RCE). The vulnerability requires the victim to open a malicious file, which means user interaction is necessary, but no privileges are required to exploit it. The CVSS 3.1 base score is 7.8, indicating high severity, with attack vector local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), and impacts on confidentiality, integrity, and availability all rated high (C:H/I:H/A:H). The vulnerability was published on June 11, 2024, and no known exploits have been reported in the wild yet. The root cause is the improper handling of symbolic links, which can be abused to redirect file operations to attacker-controlled locations, enabling execution of arbitrary code within the context of the user running Office. This can lead to full system compromise if successful. The vulnerability is particularly concerning because Microsoft Office is widely used in enterprise environments, and exploitation could facilitate lateral movement, data exfiltration, or deployment of ransomware.

For European organizations, the impact of CVE-2024-30104 can be significant due to the widespread deployment of Microsoft Office 2019 in corporate, governmental, and critical infrastructure sectors. Successful exploitation could lead to remote code execution, allowing attackers to gain unauthorized access to sensitive data, modify or destroy information, and 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, and potential ransomware attacks. The requirement for user interaction means phishing campaigns or social engineering could be effective attack vectors, increasing the risk in sectors with high email usage. Additionally, the local attack vector implies that attackers need some form of access to deliver the malicious document, which could be achieved through compromised email accounts or insider threats. The absence of known exploits in the wild provides a window for proactive defense, but the high severity score underscores the urgency for mitigation.

1. Apply official Microsoft patches immediately once they are released for this vulnerability to ensure the flaw is remediated at the source. 2. Until patches are available, implement strict controls on the handling of symbolic links and shortcuts within enterprise environments, including disabling or restricting symbolic link creation and resolution where feasible. 3. Enhance email filtering and attachment scanning to detect and block suspicious Office documents containing unusual link structures. 4. Conduct targeted user awareness training focused on recognizing phishing attempts and the risks of opening unsolicited or unexpected Office files. 5. Employ endpoint detection and response (EDR) solutions to monitor for anomalous file access patterns and potential exploitation attempts related to symbolic link abuse. 6. Enforce the principle of least privilege to limit the impact of any successful exploitation by restricting user permissions on file systems and network shares. 7. Use application whitelisting and sandboxing technologies to contain the execution of Office processes and limit the potential for code execution outside expected parameters. 8. Regularly audit and review file system permissions and symbolic link usage to detect and remediate any unauthorized changes.