CVE-2025-43734 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 of Liferay DXP from 2024.Q1.1 through 2025.Q1.10. The vulnerability arises due to improper neutralization of input during web page generation (CWE-79), specifically in the handling of the “first display label” field within the configuration of a custom sort widget. An authenticated remote attacker can inject malicious JavaScript code into this field. When the affected page is refreshed, the injected script is reflected and executed by the clay button taglib component, which is responsible for rendering UI elements. This reflected XSS flaw does not require elevated privileges (no authentication required), but does require user interaction (the victim must refresh the page or visit the crafted URL). The CVSS 4.0 base score is 5.1 (medium severity), indicating a moderate risk. The vulnerability impacts confidentiality and integrity by enabling script execution in the context of the victim’s browser, potentially allowing session hijacking, credential theft, or unauthorized actions within the portal. No known exploits are currently reported in the wild, and no patches have been linked yet, suggesting that mitigation may require vendor updates or configuration changes. The vulnerability’s exploitation vector is network-based with low attack complexity and no privileges required, but user interaction is necessary to trigger the payload execution.

For European organizations using Liferay Portal or Liferay DXP, this vulnerability poses a moderate security risk. Liferay is widely used in enterprise content management, intranet portals, and digital experience platforms across various sectors including government, finance, education, and healthcare in Europe. Successful exploitation could lead to session hijacking, unauthorized access to sensitive information, or execution of arbitrary actions on behalf of legitimate users. This could result in data breaches, reputational damage, and compliance violations under regulations such as GDPR. Since the vulnerability requires user interaction and an authenticated attacker can inject malicious scripts, insider threats or compromised accounts could be leveraged to exploit this flaw. The reflected XSS could also be used as a stepping stone for further attacks such as phishing or malware distribution within corporate networks. The absence of known exploits currently reduces immediate risk, but the presence of the vulnerability in widely deployed versions means organizations should prioritize mitigation to avoid future exploitation.

1. Apply official patches or updates from Liferay as soon as they become available to address CVE-2025-43734. 2. In the interim, restrict access to the configuration interfaces of custom sort widgets to trusted administrators only, minimizing the risk of malicious input injection. 3. Implement strict input validation and output encoding on the “first display label” field and other user-controllable inputs within the portal configuration to neutralize potentially malicious scripts. 4. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in the portal environment. 5. Monitor logs for unusual activity related to widget configuration changes or unexpected script injections. 6. Educate users and administrators about the risks of reflected XSS and the importance of cautious interaction with links and portal pages. 7. Consider deploying Web Application Firewalls (WAFs) with rules tailored to detect and block reflected XSS payloads targeting Liferay Portal components. 8. Review and tighten authentication and session management controls to reduce the risk of account compromise that could facilitate exploitation.