CVE-2025-67545 is a stored Cross-site Scripting (XSS) vulnerability identified in FirePlugins FireBox, a web application product, affecting versions up to and including 3.1.0-free. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, which allows malicious scripts to be stored on the server and subsequently executed in the browsers of other users who access the affected pages. This type of vulnerability can lead to unauthorized actions such as session hijacking, theft of sensitive information, or execution of arbitrary code within the context of the victim's browser. The CVSS v3.1 base score is 6.5, reflecting medium severity, with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), user interaction (UI:R), and a scope change (S:C) that affects confidentiality, integrity, and availability to a limited extent (C:L/I:L/A:L). Exploitation requires an attacker to have some level of authenticated access and to trick a user into interacting with the malicious content. Currently, there are no known exploits in the wild, and no official patches have been linked yet. The vulnerability was published on December 9, 2025, and assigned by Patchstack. Given the nature of stored XSS, the risk is significant in environments where multiple users interact with the FireBox interface, especially if sensitive data or administrative functions are accessible.

For European organizations, this vulnerability poses a risk of unauthorized data disclosure, session hijacking, and potential compromise of user accounts or administrative functions within FireBox. Since the vulnerability allows stored XSS, attackers can persistently inject malicious scripts that affect multiple users, potentially leading to widespread impact within an organization. This can undermine confidentiality by exposing sensitive information, integrity by enabling unauthorized actions, and availability if attackers disrupt normal operations. Organizations in sectors such as finance, healthcare, and critical infrastructure that rely on FireBox for web services or internal tools are particularly vulnerable. The requirement for some privileges and user interaction limits the ease of exploitation but does not eliminate risk, especially in environments with many users or where social engineering is feasible. The absence of known exploits in the wild currently reduces immediate threat but does not preclude future attacks. Failure to address this vulnerability could lead to reputational damage, regulatory penalties under GDPR if personal data is compromised, and operational disruptions.

European organizations should implement the following specific mitigations: 1) Monitor FirePlugins announcements closely and apply official patches or updates as soon as they become available to address CVE-2025-67545. 2) In the interim, restrict user privileges to the minimum necessary, especially limiting the ability to submit or modify content that is rendered in web pages. 3) Employ web application firewalls (WAFs) with custom rules to detect and block suspicious input patterns indicative of XSS payloads targeting FireBox. 4) Conduct thorough input validation and output encoding on all user-supplied data within FireBox configurations or customizations, if possible. 5) Educate users about the risks of interacting with unexpected or suspicious content within FireBox interfaces to reduce successful social engineering. 6) Regularly audit logs and monitor for unusual activity that could indicate exploitation attempts. 7) Consider isolating FireBox instances or limiting network exposure to reduce attack surface. These steps go beyond generic advice by focusing on privilege management, proactive monitoring, and layered defenses specific to the FireBox environment.