CVE-2024-48932 is a security vulnerability classified under CWE-284 (Improper Access Control) found in IceWhaleTech's ZimaOS, an operating system forked from CasaOS designed for Zima devices and x86-64 systems with UEFI firmware. The vulnerability exists in versions prior to 1.5.0, where the API endpoint at http://<Server-ip>/v1/users/name does not enforce authentication or authorization checks, allowing any unauthenticated user to retrieve sensitive information such as usernames. This lack of access control enables attackers to enumerate valid usernames on the system, which is a critical first step in targeted attacks like brute-force password guessing or spear-phishing campaigns. The vulnerability is remotely exploitable over the network without requiring user interaction or privileges, increasing its risk profile. Although the CVSS v3.1 base score is 5.3 (medium severity), reflecting limited impact on confidentiality only and no impact on integrity or availability, the exposure of usernames can significantly aid attackers in compromising accounts. No patches or fixes have been released at the time of disclosure, and no known exploits are reported in the wild. The vulnerability affects all ZimaOS deployments running versions below 1.5.0, which may be used in various organizational environments. The technical root cause is insufficient enforcement of access control policies on the user enumeration API endpoint, violating the principle of least privilege and exposing sensitive user data unnecessarily.

For European organizations, this vulnerability poses a moderate risk primarily by enabling attackers to gather valid usernames without authentication. This information can be leveraged to launch credential stuffing, brute-force attacks, or social engineering campaigns targeting employees or system users. While the vulnerability does not directly compromise system integrity or availability, the indirect consequences can lead to unauthorized access if attackers successfully guess or phish credentials. Organizations in sectors with high-value targets or sensitive data, such as finance, government, or critical infrastructure, could face increased risk of targeted attacks. The lack of a patch means organizations must rely on compensating controls, increasing operational overhead. Additionally, exposure of usernames could violate data protection regulations like GDPR if usernames are considered personal data, potentially leading to compliance issues and reputational damage.

Since no official patches are available, European organizations should implement immediate compensating controls. These include restricting network access to the vulnerable API endpoint via firewall rules or network segmentation to limit exposure to trusted users only. Deploying Web Application Firewalls (WAFs) with custom rules to block unauthenticated requests to /v1/users/name can reduce attack surface. Monitoring and logging access to this endpoint will help detect enumeration attempts early. Organizations should enforce strong authentication and multi-factor authentication (MFA) on all user accounts to mitigate risks from credential guessing attacks. Usernames should be treated as sensitive information internally, and security awareness training should be conducted to reduce phishing susceptibility. Regularly auditing ZimaOS versions and planning for timely upgrades once patches are released is critical. Finally, consider deploying intrusion detection systems (IDS) tuned to detect enumeration patterns against this API.