CVE-2025-53728 is a vulnerability classified under CWE-200, indicating an exposure of sensitive information to unauthorized actors. This vulnerability affects Microsoft Dynamics 365 (on-premises) version 9.1, specifically impacting version 9.0 as noted in the affected versions. The flaw allows an attacker without privileges (PR:N) and without authentication to disclose sensitive information over a network (AV:N), requiring only user interaction (UI:R). The vulnerability does not impact the integrity or availability of the system but compromises confidentiality with high impact (C:H). The CVSS 3.1 base score is 6.5, categorized as medium severity. The vulnerability is exploitable remotely with low attack complexity (AC:L), and the scope remains unchanged (S:U). No known exploits are currently reported in the wild, and no patches have been linked yet. The exposure of sensitive data could include business-critical or personal information managed within Dynamics 365, potentially leading to information leakage that could be leveraged for further attacks or compliance violations. Since the vulnerability requires user interaction, exploitation might involve phishing or social engineering to trick users into triggering the data exposure. The lack of required privileges means that even unauthenticated attackers can attempt exploitation, increasing the risk profile. The vulnerability is particularly relevant for organizations relying on on-premises deployments of Microsoft Dynamics 365, which is widely used for customer relationship management (CRM) and enterprise resource planning (ERP) functions.

For European organizations, the exposure of sensitive information through this vulnerability could have significant consequences. Many European companies use Microsoft Dynamics 365 for managing customer data, sales, and operational workflows, often including personal data protected under GDPR. Unauthorized disclosure could lead to breaches of privacy regulations, resulting in legal penalties and reputational damage. Additionally, leaked information might facilitate targeted attacks such as spear phishing or business email compromise. The medium severity rating reflects the balance between the ease of exploitation and the impact limited to confidentiality. However, the potential for cascading effects, such as enabling further intrusions or fraud, elevates the risk. Organizations in sectors like finance, healthcare, manufacturing, and public administration, which often handle sensitive or regulated data, are particularly vulnerable. The on-premises nature of the affected product means that patching and mitigation depend on the organization's internal IT policies and responsiveness, which can vary widely across Europe.

European organizations should prioritize the following specific mitigation steps: 1) Conduct an immediate inventory to identify all instances of Microsoft Dynamics 365 (on-premises) version 9.0 and 9.1 deployments. 2) Monitor official Microsoft channels for patches or security advisories related to CVE-2025-53728 and apply updates promptly once available. 3) Implement network segmentation and restrict external access to Dynamics 365 servers to minimize exposure to unauthorized actors. 4) Enhance user awareness training focusing on social engineering and phishing risks, since exploitation requires user interaction. 5) Review and tighten access controls and logging to detect unusual access patterns or data exfiltration attempts. 6) Employ web application firewalls (WAFs) or intrusion detection/prevention systems (IDS/IPS) to monitor and block suspicious network traffic targeting Dynamics 365 services. 7) Consider temporary compensating controls such as disabling or limiting features that expose sensitive information until patches are applied. 8) Regularly audit data flows and sensitive information exposure within Dynamics 365 to identify and remediate unnecessary data exposure. These measures go beyond generic advice by focusing on the specific context of on-premises Dynamics 365 deployments and the nature of this vulnerability.