CVE-2025-54596 is a medium-severity vulnerability classified under CWE-863 (Incorrect Authorization) affecting Abnormal AI's Abnormal Security product version 1.0 and earlier, specifically before the patch date of 2025-02-19. The vulnerability exists in the API endpoint /v1.0/rbac/users_v2/{USER_ID}/, which handles role-based access control (RBAC) user management. Due to improper authorization checks, an authenticated user with certain privileges can downgrade the privileges of other user accounts without proper authorization. This means that an attacker who already has some level of access (low privilege) can reduce the permissions of other users, potentially disrupting their ability to perform security functions or access critical features. The CVSS v3.1 score is 4.3 (medium), reflecting that the attack vector is network-based (AV:N), requires low attack complexity (AC:L), but requires privileges (PR:L) and no user interaction (UI:N). The impact affects integrity (I:L) but not confidentiality or availability. No known exploits are currently reported in the wild, and no patches or mitigation links are provided in the data. The vulnerability could be exploited remotely by an authenticated user to manipulate RBAC settings, potentially weakening the security posture of an organization by disabling or limiting other users' roles, which may include security administrators or privileged users. This could lead to reduced oversight, delayed incident response, or unauthorized changes going unnoticed.

For European organizations, this vulnerability poses a risk primarily to the integrity of user permissions within the Abnormal Security platform, which is used for email security and threat detection. Downgrading privileges of other users could allow attackers or malicious insiders to reduce the effectiveness of security teams by limiting their access or capabilities, potentially leading to gaps in threat monitoring or response. This could increase the risk of successful phishing, malware, or other email-based attacks going undetected. Since Abnormal Security is a cloud-based email security solution, organizations relying on it for protecting sensitive communications and compliance with GDPR and other regulations could face increased risk of data exposure indirectly due to weakened internal controls. The vulnerability does not directly impact confidentiality or availability but undermines the integrity of access controls, which is critical for maintaining a secure environment. The absence of known exploits suggests limited immediate risk, but the potential for privilege manipulation warrants prompt attention, especially in sectors with high regulatory requirements such as finance, healthcare, and government within Europe.

Given the lack of an official patch link, European organizations using Abnormal Security version 1.0 should take the following specific steps: 1) Immediately review and audit all user roles and permissions within the Abnormal Security platform to identify any unauthorized changes or privilege downgrades. 2) Restrict the number of users with privileges sufficient to exploit this vulnerability (i.e., limit users with permission to modify RBAC settings). 3) Implement enhanced monitoring and alerting on RBAC changes to detect suspicious privilege modifications in real time. 4) Enforce strong authentication mechanisms (e.g., multi-factor authentication) for all users with elevated privileges to reduce risk of credential compromise. 5) Contact Abnormal AI support to confirm patch availability or planned remediation timelines and apply patches as soon as they are released. 6) Consider compensating controls such as additional logging, manual approval workflows for role changes, or temporary suspension of non-critical user modifications until the vulnerability is resolved. 7) Educate administrators on the risks of privilege downgrades and encourage vigilance in managing user roles.