CVE-2024-38023 is a vulnerability in Microsoft SharePoint Enterprise Server 2016 (version 16.0.0) that arises from improper deserialization of untrusted data, classified under CWE-502. Deserialization vulnerabilities occur when untrusted input is deserialized by an application without sufficient validation, allowing attackers to manipulate the process to execute arbitrary code. In this case, the flaw enables remote code execution (RCE) with high privileges, meaning an attacker who already has some level of access (privileged user) can exploit this vulnerability to run malicious code on the server remotely without requiring user interaction. The vulnerability has a CVSS 3.1 base score of 7.2, indicating a high severity level due to its network attack vector, low attack complexity, and high impact on confidentiality, integrity, and availability. The vulnerability was publicly disclosed on July 9, 2024, and while no exploits are currently known in the wild, the potential for exploitation exists given the critical nature of SharePoint in enterprise environments. SharePoint Enterprise Server 2016 is widely used for document management and collaboration in many organizations, making this vulnerability particularly concerning. The lack of an available patch at the time of disclosure increases the urgency for organizations to implement interim mitigations and monitor for suspicious activity. The vulnerability requires high privileges to exploit, which somewhat limits the attack surface but does not eliminate the risk, especially in environments where privileged accounts may be compromised or misused.

For European organizations, the impact of CVE-2024-38023 could be significant. SharePoint Enterprise Server 2016 is commonly deployed in enterprises, government agencies, and educational institutions across Europe for collaboration and document management. Successful exploitation could lead to full system compromise, allowing attackers to steal sensitive data, disrupt operations, or move laterally within networks. The confidentiality, integrity, and availability of critical business information could be severely affected. Given the high privileges required, the threat is particularly relevant in environments where insider threats or credential compromise are concerns. The disruption of SharePoint services could impact business continuity and regulatory compliance, especially under GDPR and other data protection laws. Additionally, the potential for ransomware or other malware deployment via this vulnerability could exacerbate the damage. Organizations relying heavily on SharePoint for internal workflows and document sharing are at increased risk of operational and reputational harm.

Since no official patch was available at the time of disclosure, European organizations should implement the following specific mitigations: 1) Restrict and monitor privileged account usage to reduce the risk of exploitation by insiders or compromised credentials. 2) Employ network segmentation to isolate SharePoint servers from less trusted network zones and limit exposure to external networks. 3) Implement strict input validation and filtering on data entering SharePoint to reduce the risk of malicious serialized objects being processed. 4) Enable and review detailed logging and monitoring on SharePoint servers to detect unusual deserialization activity or anomalous remote code execution attempts. 5) Use application whitelisting and endpoint protection solutions to prevent unauthorized code execution on SharePoint servers. 6) Prepare for rapid patch deployment once Microsoft releases an official fix, including testing in staging environments to minimize downtime. 7) Conduct regular security awareness training focused on credential security and phishing to prevent privilege escalation. 8) Consider temporary disabling or limiting features that process serialized data if feasible until patches are applied.