CVE-2024-5401 is a vulnerability identified in the WebAPI component of Synology DiskStation Manager (DSM) and Synology Unified Controller (DSMUC). The flaw arises from improper control over dynamically-managed code resources, which allows remote authenticated users to escalate their privileges without consent. Specifically, this vulnerability affects DSM versions prior to 7.1.1-42962-8, 7.2.1-69057-2, and 7.2.2-72806, as well as DSMUC versions before 3.1.4-23079. The exploitation vector involves authenticated users leveraging unspecified methods to gain higher privileges, potentially enabling unauthorized modification of system settings or code execution with elevated rights. The CVSS 3.1 base score of 4.3 indicates a medium severity, with the vector string AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N showing that the attack is network-based, requires low attack complexity, and privileges but no user interaction, impacting integrity but not confidentiality or availability. No public exploits or active exploitation have been reported, but the vulnerability poses a risk in environments where multiple users have authenticated access to DSM. The root cause is related to insufficient validation or control of dynamically loaded code resources within the WebAPI, which could be abused to escalate privileges. Synology NAS devices are widely deployed for storage and network management in enterprises and SMBs, making this a relevant threat for organizations relying on these devices for critical data and services.

For European organizations, this vulnerability could lead to unauthorized privilege escalation on Synology NAS devices, potentially allowing attackers with valid credentials to alter system configurations, deploy malicious code, or interfere with data integrity. While confidentiality and availability are not directly impacted, integrity compromises could facilitate further attacks, data tampering, or persistence mechanisms. Organizations using Synology DSM in multi-user environments or with exposed management interfaces are particularly at risk. Given the widespread use of Synology NAS in European SMBs, enterprises, and public sector entities for file storage, backup, and application hosting, exploitation could disrupt business operations or lead to compliance issues under regulations such as GDPR if data integrity is compromised. The requirement for authentication limits exposure but does not eliminate risk, especially in cases of credential compromise or insider threats. The lack of known exploits in the wild reduces immediate risk but underscores the importance of proactive patching and access control.

1. Immediately update Synology DSM to versions 7.1.1-42962-8, 7.2.1-69057-2, 7.2.2-72806 or later, and DSMUC to version 3.1.4-23079 or later, as these contain patches addressing the vulnerability. 2. Restrict access to DSM management interfaces to trusted internal networks or VPNs to reduce exposure to authenticated attackers. 3. Enforce strong authentication policies, including multi-factor authentication (MFA), to reduce the risk of credential compromise. 4. Regularly audit user accounts and privileges on Synology devices to ensure minimal necessary access and promptly remove unused or suspicious accounts. 5. Monitor DSM logs for unusual privilege escalation attempts or anomalous activities indicative of exploitation attempts. 6. Implement network segmentation to isolate NAS devices from general user networks where possible. 7. Educate users about the risks of credential sharing and phishing attacks that could lead to unauthorized authentication. 8. Consider deploying endpoint detection and response (EDR) solutions to detect suspicious behavior on NAS devices. These steps go beyond generic advice by focusing on access control, authentication hardening, and proactive monitoring tailored to the Synology DSM environment.