CVE-2025-43699 is a medium-severity vulnerability identified in Salesforce OmniStudio, specifically affecting the FlexCards component prior to the Spring 2025 release. The vulnerability is categorized under CWE-602, which refers to Client-Side Enforcement of Server-Side Security. In this context, the security control that should be enforced on the server side is instead being enforced on the client side, allowing an attacker to bypass required permission checks. This means that unauthorized users could potentially access or interact with FlexCards functionalities without proper authorization because the client-side enforcement can be manipulated or circumvented. The vulnerability has a CVSS 3.1 base score of 5.3, indicating a medium impact, with the vector string AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N. This translates to a network attack vector with low attack complexity, no privileges required, no user interaction needed, unchanged scope, and limited confidentiality impact (partial information disclosure). There is no known exploit in the wild at the time of publication, and no official patches have been linked yet. The root cause lies in improper security design where critical permission checks are not enforced on the server side, which is a fundamental security best practice violation. Attackers exploiting this vulnerability could gain unauthorized read access to data or functionality within OmniStudio FlexCards, potentially leading to information leakage or unauthorized data exposure within Salesforce environments.

For European organizations using Salesforce OmniStudio, this vulnerability poses a risk of unauthorized data exposure. Since OmniStudio is often used for building customer-facing and internal applications with dynamic data presentation (FlexCards), bypassing permission checks could lead to leakage of sensitive business or customer information. This could impact confidentiality and compliance with data protection regulations such as GDPR. Although the vulnerability does not allow data modification or denial of service, unauthorized read access could still result in reputational damage, regulatory penalties, and loss of customer trust. The fact that no authentication or user interaction is required increases the risk, as attackers could exploit this remotely over the network. Organizations relying heavily on Salesforce OmniStudio for critical business processes or customer data management are particularly at risk. The medium severity score reflects the limited scope of impact (confidentiality only) but the ease of exploitation and network accessibility make it a relevant threat to address promptly.

European organizations should immediately review their use of Salesforce OmniStudio FlexCards and identify instances running versions prior to Spring 2025. Until an official patch is released, organizations should implement compensating controls such as restricting network access to OmniStudio environments to trusted IP ranges and enforcing strict authentication and authorization at higher application layers. Monitoring and logging access to FlexCards components should be enhanced to detect anomalous or unauthorized access attempts. Salesforce administrators should stay alert for official security advisories and apply patches as soon as they become available. Additionally, organizations should conduct security reviews to ensure that no other client-side enforced security controls exist and that all critical permission checks are properly enforced server-side. Training developers and administrators on secure design principles to avoid client-side enforcement of security is also recommended to prevent similar issues in customizations or integrations.