CVE-2025-0691 is a medium severity vulnerability classified under CWE-284 (Improper Access Control) affecting Devolutions Server versions 2025.1.10.0 and earlier. The issue resides in the permissions component of the server, where an authenticated user can bypass the "Edit permission" restriction by circumventing client-side validation mechanisms. This means that although the server is intended to restrict certain users from editing permissions, the enforcement relies partially on client-side checks that can be manipulated or bypassed by a malicious authenticated user. The vulnerability does not affect confidentiality or availability but impacts integrity, as unauthorized users can modify permission settings, potentially escalating privileges or altering access controls improperly. The CVSS v3.1 base score is 5.0 (medium), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), requiring low privileges (PR:L), no user interaction (UI:N), and scope changed (S:C). The scope change indicates that the vulnerability affects resources beyond the initially vulnerable component, potentially impacting other parts of the system. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was publicly disclosed on June 5, 2025.

For European organizations using Devolutions Server, this vulnerability poses a risk primarily to the integrity of access control configurations. Unauthorized modification of permissions could allow attackers or malicious insiders to escalate privileges, gain unauthorized access to sensitive systems or data, or disrupt operational security policies. This could lead to lateral movement within networks, exposure of confidential information, or disruption of secure administrative workflows. Since Devolutions Server is often used for managing remote connections and privileged access, improper permission changes could undermine the security of critical infrastructure and sensitive environments. The lack of impact on confidentiality and availability limits the scope of damage but does not eliminate the risk of privilege escalation and unauthorized access. Organizations in sectors with strict regulatory requirements for access control and auditability, such as finance, healthcare, and government, may face compliance risks if this vulnerability is exploited.

European organizations should implement the following specific mitigation steps: 1) Immediately audit current permission settings within Devolutions Server to detect any unauthorized changes. 2) Restrict authenticated user roles to the minimum necessary privileges, especially limiting access to permission management functions. 3) Monitor logs for unusual permission modification activities or access patterns that could indicate exploitation attempts. 4) Apply strict network segmentation and access controls to limit which users can reach the Devolutions Server interface. 5) Enforce multi-factor authentication (MFA) for all users with permission editing capabilities to reduce risk from compromised credentials. 6) Since no patch is currently linked, engage with Devolutions support or vendor channels to obtain updates or workarounds as soon as they become available. 7) Consider implementing server-side validation enhancements or compensating controls to prevent client-side bypasses. 8) Educate administrators and users about the risks of client-side validation reliance and encourage reporting of suspicious behavior. These steps go beyond generic advice by focusing on privilege minimization, monitoring, and compensating controls specific to the nature of this vulnerability.