CVE-2025-43753 is a reflected cross-site scripting (XSS) vulnerability identified in multiple versions of the Liferay Portal and Liferay DXP products. Specifically, it affects Liferay Portal versions 7.4.3.32 through 7.4.3.132 and Liferay DXP versions spanning 2024.Q1.1 through 2025.Q1.7, including various quarterly updates and 7.4 updates 32 through 92. The vulnerability arises due to improper neutralization of input during web page generation (CWE-79), allowing a remote authenticated user to inject malicious JavaScript code into the embedded message field within the form container. This reflected XSS flaw means that when the crafted input is submitted, the malicious script is reflected back in the HTTP response and executed in the context of the victim's browser. The CVSS 4.0 base score is 2.1, indicating a low severity primarily because exploitation requires high privileges (remote authenticated user), high attack complexity, and no user interaction is needed. The impact on confidentiality and integrity is low, with limited availability impact. No known exploits are currently reported in the wild, and no patches or mitigation links are provided in the data. The vulnerability could be leveraged to execute arbitrary JavaScript in the context of the affected web application, potentially leading to session hijacking, unauthorized actions, or information disclosure within the scope of the authenticated user's privileges. However, the requirement for authenticated access and high complexity reduces the likelihood of widespread exploitation.

For European organizations using Liferay Portal or Liferay DXP, this vulnerability poses a moderate risk primarily in environments where multiple users have authenticated access to the portal, such as intranet portals, customer service platforms, or collaboration tools. Successful exploitation could allow attackers to execute malicious scripts that may steal session tokens, perform unauthorized actions on behalf of users, or manipulate displayed content. This could lead to data leakage, unauthorized transactions, or reputational damage. Given that Liferay is widely used in enterprise and government sectors across Europe for content management and digital experience platforms, the vulnerability could affect sensitive internal communications or customer data if exploited. However, the low CVSS score and the requirement for high privileges limit the scope of impact to users with authenticated access, reducing the risk of mass exploitation. Organizations with strict access controls and monitoring may further reduce the impact. Still, the presence of this vulnerability highlights the need for vigilance in patch management and input validation to prevent potential lateral movement or privilege escalation within the portal environment.

1. Apply official patches or updates from Liferay as soon as they become available to address this vulnerability. 2. Implement strict input validation and output encoding on all user-supplied data, especially in the embedded message fields and form containers, to prevent injection of malicious scripts. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts within the portal application. 4. Enforce the principle of least privilege by limiting user permissions to only those necessary, reducing the number of users who can exploit this vulnerability. 5. Monitor logs and user activity for unusual behavior indicative of XSS exploitation attempts, such as unexpected JavaScript execution or anomalous form submissions. 6. Conduct regular security assessments and penetration testing focusing on XSS vulnerabilities in the portal environment. 7. Educate users about the risks of XSS and encourage reporting of suspicious portal behavior. 8. If immediate patching is not possible, consider temporary mitigation such as disabling or restricting the vulnerable embedded message field functionality or applying web application firewall (WAF) rules to detect and block malicious payloads targeting this vector.