CVE-2025-3941 is a medium-severity vulnerability identified in the Tridium Niagara Framework and Niagara Enterprise Security products running on Windows platforms. The root cause is improper handling of Windows Alternate Data Streams (ADS), specifically the ::DATA stream, which allows an attacker to manipulate input data. Alternate Data Streams are a feature of the NTFS file system that enable files to contain multiple streams of data, which can be used to hide or embed malicious content. In this case, the Niagara Framework versions prior to 4.14.2, 4.15.1, and 4.10.11 do not properly validate or sanitize input data coming from ADS, leading to potential input data manipulation. This vulnerability is classified under CWE-69, which relates to improper handling of input data leading to incorrect program behavior. The CVSS v3.1 base score is 5.4, indicating a medium severity level. The attack vector is network-based (AV:N), requiring low attack complexity (AC:L) and privileges (PR:L), but no user interaction (UI:N). The impact affects confidentiality and integrity but not availability (C:L/I:L/A:N). There are no known exploits in the wild at this time, and no direct patch links provided, but Tridium recommends upgrading to patched versions 4.14.2u2, 4.15.u1, or 4.10u.11 to remediate the issue. The vulnerability could allow an attacker with some level of access (privileged user) to manipulate data inputs via ADS, potentially leading to unauthorized information disclosure or data tampering within the Niagara Framework environment. Given that Niagara Framework is widely used for building automation and industrial control systems, this vulnerability could have significant implications if exploited.

For European organizations, especially those in critical infrastructure sectors such as energy, manufacturing, and building management, this vulnerability poses a risk to the integrity and confidentiality of operational data managed by the Niagara Framework. Since the framework is commonly deployed in smart building automation, HVAC control, and industrial IoT environments, exploitation could lead to unauthorized data manipulation, potentially causing incorrect system behavior or leakage of sensitive operational information. Although availability is not directly impacted, the integrity compromise could indirectly affect system reliability and safety. European organizations with network-exposed Niagara installations or those with privileged users who could be targeted by attackers are at higher risk. The medium CVSS score reflects that exploitation requires some privileges, limiting the attack surface to insiders or attackers who have gained initial footholds. However, given the critical nature of the systems managed by Niagara Framework, even limited data manipulation could have cascading effects on physical processes and security monitoring.

1. Immediate upgrade to the patched versions recommended by Tridium: Niagara Framework and Enterprise Security versions 4.14.2u2, 4.15.u1, or 4.10u.11. 2. Implement strict access controls and monitoring on systems running Niagara Framework to limit privileged user accounts and detect anomalous activities related to file system operations and ADS usage. 3. Employ network segmentation to isolate Niagara Framework systems from general IT networks, reducing exposure to remote attackers. 4. Conduct regular file system audits to detect suspicious use of Alternate Data Streams on Windows hosts. 5. Enhance endpoint security solutions to monitor and alert on ADS manipulations or unusual file metadata changes. 6. Train system administrators and operators on the risks associated with ADS and the importance of applying vendor patches promptly. 7. Review and harden input validation mechanisms in custom integrations or scripts interacting with the Niagara Framework to prevent exploitation of ADS-related input manipulation.