CVE-2024-38023 is a vulnerability identified in Microsoft SharePoint Enterprise Server 2016 (version 16.0.0) that stems from improper handling of deserialization of untrusted data, classified under CWE-502. Deserialization vulnerabilities occur when an application deserializes data from untrusted sources without sufficient validation, allowing attackers to craft malicious payloads that, when deserialized, can execute arbitrary code. In this case, the vulnerability enables remote code execution (RCE) on the SharePoint server. The CVSS 3.1 base score is 7.2, indicating a high severity level, with the attack vector being network-based (AV:N), requiring low attack complexity (AC:L), but necessitating high privileges (PR:H) and no user interaction (UI:N). The scope remains unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). The vulnerability is currently published with no known exploits in the wild, but its presence in a widely used enterprise collaboration platform makes it a significant risk. SharePoint servers often hold sensitive organizational data and are integrated into critical business workflows, amplifying the potential damage from exploitation. The lack of available patches at the time of publication necessitates immediate risk mitigation through alternative controls. Given the nature of the vulnerability, attackers with administrative or elevated privileges could leverage this flaw to execute arbitrary code remotely, potentially leading to full system compromise, data theft, or disruption of services.

For European organizations, this vulnerability poses a significant threat due to the widespread use of Microsoft SharePoint Enterprise Server 2016 in enterprise environments for document management and collaboration. Exploitation could lead to unauthorized access to sensitive data, disruption of business operations, and potential lateral movement within corporate networks. The high impact on confidentiality, integrity, and availability means that critical business information could be exposed or altered, and services could be interrupted, affecting compliance with data protection regulations such as GDPR. Organizations in sectors like finance, government, healthcare, and critical infrastructure, which heavily rely on SharePoint for collaboration and document storage, are particularly at risk. The requirement for high privileges to exploit the vulnerability suggests that insider threats or attackers who have already gained elevated access could leverage this flaw to escalate their control. The absence of known exploits currently provides a window for proactive defense, but the potential for rapid weaponization remains, especially given the common targeting of Microsoft products by threat actors.

1. Monitor Microsoft’s official channels closely for the release of security patches addressing CVE-2024-38023 and apply them promptly once available. 2. Restrict administrative and elevated privilege access to SharePoint servers to the minimum necessary personnel and enforce strong authentication mechanisms, including multi-factor authentication (MFA). 3. Implement network segmentation to isolate SharePoint servers from less trusted network zones, limiting exposure to potential attackers. 4. Enable and review detailed logging and monitoring for unusual deserialization activity or anomalous behavior on SharePoint servers to detect potential exploitation attempts early. 5. Conduct regular security audits and vulnerability assessments focusing on SharePoint environments to identify and remediate configuration weaknesses. 6. Consider deploying application-layer firewalls or web application firewalls (WAFs) with custom rules to detect and block suspicious serialized payloads targeting SharePoint. 7. Educate IT and security teams about the risks associated with deserialization vulnerabilities and the importance of privilege management. 8. If possible, temporarily reduce the attack surface by disabling or limiting features that process serialized data until patches are applied.