CVE-2025-43746 is a reflected Cross-Site Scripting (XSS) vulnerability identified in multiple versions of the Liferay Portal and Liferay DXP products, specifically affecting versions 7.4.0 through 7.4.3.132 and various quarterly releases from 2024.Q1 through 2025.Q2. The vulnerability arises due to improper sanitization of user-supplied input in the parameters _com_liferay_dynamic_data_mapping_web_portlet_DDMPortlet_portletNamespace and _com_liferay_dynamic_data_mapping_web_portlet_DDMPortlet_namespace. An authenticated attacker with high privileges can inject malicious JavaScript code into these parameters, which is then reflected back in the web application response without adequate encoding or filtering. This allows the attacker to execute arbitrary scripts in the context of the victim's browser session. The CVSS 4.0 base score is 5.1, indicating a medium severity level. The attack vector is network-based, requiring no user interaction but does require the attacker to have authenticated access with high privileges. The vulnerability impacts confidentiality minimally (VC:L), with no impact on integrity or availability. No known exploits are currently reported in the wild. The vulnerability is categorized under CWE-79, which is a common web application security weakness related to improper neutralization of input leading to XSS. The lack of available patches at the time of reporting suggests that organizations should prioritize mitigation and monitoring until official fixes are released.

For European organizations using Liferay Portal or Liferay DXP, this vulnerability poses a risk primarily to internal users or administrators who have authenticated access to the portal. Successful exploitation could allow attackers to execute malicious scripts, potentially leading to session hijacking, unauthorized actions within the portal, or the theft of sensitive information accessible through the victim's session. While the vulnerability does not directly compromise system integrity or availability, the ability to run arbitrary scripts can facilitate further attacks such as privilege escalation or lateral movement within the network. Given Liferay's widespread use in European public sector agencies, financial institutions, and large enterprises for content management and collaboration, exploitation could disrupt business operations and damage organizational reputation. The requirement for high privilege authentication limits the attack surface but also means that insider threats or compromised credentials could be leveraged effectively. Additionally, the reflected nature of the XSS means that phishing or social engineering could be used to lure authenticated users into triggering the malicious payload, increasing risk.

1. Immediately review and restrict user privileges to ensure that only necessary personnel have high-level authenticated access to Liferay portals. 2. Implement strict input validation and output encoding on the affected parameters at the web application firewall (WAF) or reverse proxy level to block malicious scripts before they reach the application. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts within the portal environment. 4. Monitor logs for unusual activity related to the vulnerable parameters, including repeated or anomalous requests that may indicate exploitation attempts. 5. Educate users with high privileges about the risks of phishing and social engineering attacks that could trigger reflected XSS payloads. 6. Stay updated with Liferay vendor advisories and apply patches or updates as soon as they become available. 7. Consider deploying runtime application self-protection (RASP) solutions that can detect and block XSS attacks in real time. 8. Conduct regular security assessments and penetration testing focused on web application vulnerabilities, including reflected XSS scenarios.