CVE-2025-43815 is a reflected cross-site scripting vulnerability identified in Liferay Portal versions 7.4.3.102 through 7.4.3.110 and Liferay DXP versions 2023.Q4.0 through 2023.Q4.2 and 2023.Q3.5. The vulnerability arises from improper neutralization of user-supplied input in the com_liferay_layout_admin_web_portlet_GroupPagesPortlet_backURLTitle parameter on the page configuration page. This parameter is not adequately sanitized before being reflected in the web page, enabling remote attackers to inject arbitrary HTML or JavaScript code. The attack vector is network-based (AV:N), requiring no privileges (PR:N) or authentication (AT:N), but does require user interaction (UI:A), such as clicking a maliciously crafted URL. The impact on confidentiality and integrity is low, as the vulnerability primarily enables script injection that can lead to session hijacking, phishing, or UI manipulation. Availability is not affected. The CVSS 4.0 score is 5.1, reflecting medium severity. No public exploits have been reported yet, but the vulnerability is publicly disclosed and should be considered a risk. The flaw is categorized under CWE-79, a common web application security weakness. Liferay has not yet published patches at the time of this report, so mitigation relies on workarounds and defensive controls.

For European organizations, this vulnerability poses a risk primarily to web applications and portals built on the affected Liferay versions. Successful exploitation could allow attackers to execute arbitrary scripts in the context of authenticated users, potentially leading to session hijacking, credential theft, or phishing attacks. This can undermine user trust and lead to data exposure or unauthorized actions within the portal. Organizations in sectors such as government, finance, healthcare, and large enterprises that rely on Liferay Portal for intranet or customer-facing services are particularly at risk. The impact on operational continuity is limited, but reputational damage and compliance risks (e.g., GDPR violations if personal data is exposed) are significant. Since no authentication is required for exploitation, the attack surface is broad, especially if users can be socially engineered to click malicious links. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, as attackers may develop exploits rapidly after disclosure.

1. Monitor Liferay’s official security advisories and apply vendor patches promptly once released for the affected versions. 2. Implement strict input validation and output encoding on all user-supplied parameters, especially the com_liferay_layout_admin_web_portlet_GroupPagesPortlet_backURLTitle parameter, to prevent script injection. 3. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in the browser context. 4. Educate users about the risks of clicking untrusted links and implement email filtering to reduce phishing attempts. 5. Use web application firewalls (WAFs) with rules targeting reflected XSS patterns to detect and block malicious requests. 6. Conduct regular security assessments and penetration testing focusing on web application vulnerabilities. 7. Consider upgrading to newer Liferay versions that are not affected by this vulnerability if patches are delayed. 8. Review and harden portal configuration to minimize exposure of sensitive parameters in URLs.