CVE-2025-4983 is a high-severity stored Cross-site Scripting (XSS) vulnerability identified in Dassault Systèmes' City Referential Manager, specifically affecting the Release 3DEXPERIENCE R2025x Golden version. This vulnerability arises from improper neutralization of input during web page generation (CWE-79), allowing an attacker to inject malicious script code that is persistently stored and subsequently executed in the context of other users' browsers when they access affected pages. The vulnerability requires low attack complexity (AC:L), but does require privileges (PR:L) and user interaction (UI:R) to exploit, and it impacts confidentiality and integrity with no direct impact on availability. The vulnerability scope is changed (S:C), indicating that the exploit can affect resources beyond the initially vulnerable component. The CVSS v3.1 base score is 8.7, reflecting a high severity level. Although no known exploits are currently reported in the wild, the potential for attackers to hijack user sessions, steal sensitive data, or perform unauthorized actions within the City Referential Manager environment is significant. The vulnerability is particularly critical in environments where City Referential Manager is used to manage urban data and infrastructure, as attackers could leverage the XSS flaw to compromise administrative users or other privileged roles. The lack of available patches at the time of publication further increases the urgency for mitigation and monitoring. Given the nature of stored XSS, the attack vector is network-based, and exploitation requires an authenticated user to interact with malicious content, which could be introduced via crafted input fields or data uploads within the application.

For European organizations using Dassault Systèmes City Referential Manager, this vulnerability poses a substantial risk to the confidentiality and integrity of sensitive urban and infrastructure data. Successful exploitation could lead to session hijacking, unauthorized data access, or manipulation of city management information, potentially disrupting critical services or decision-making processes. Given the strategic importance of smart city management and urban planning in Europe, such an attack could have cascading effects on public safety, resource allocation, and citizen services. Additionally, compliance with GDPR and other data protection regulations means that any data breach resulting from this vulnerability could lead to significant legal and financial penalties. The requirement for user interaction and privileges to exploit somewhat limits the attack surface but does not eliminate the risk, especially in environments with multiple users having varying levels of access. The absence of known exploits in the wild currently provides a window for proactive defense but should not lead to complacency.

1. Immediate implementation of strict input validation and output encoding on all user-supplied data within City Referential Manager to prevent injection of malicious scripts. 2. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers accessing the application. 3. Enforce the principle of least privilege by reviewing and limiting user permissions, ensuring that only necessary users have elevated access that could be exploited. 4. Conduct thorough code reviews and security testing focusing on areas where user input is reflected or stored. 5. Monitor application logs and user activity for unusual behavior indicative of attempted XSS exploitation. 6. Engage with Dassault Systèmes for timely patch releases and apply them as soon as they become available. 7. Educate users on recognizing suspicious inputs and the risks of interacting with untrusted content within the application. 8. Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block XSS payloads targeting the City Referential Manager. 9. Regularly update and harden the underlying web server and platform components to reduce ancillary attack vectors.