CVE-2024-25147 is a cross-site scripting (XSS) vulnerability identified in Liferay Portal versions 7.2.0 through 7.4.1, including Liferay DXP 7.3 prior to service pack 3 and 7.2 before fix pack 15, as well as older unsupported versions. The vulnerability arises from improper neutralization of input during web page generation, specifically in the HtmlUtil.escapeJsLink function. This function is responsible for escaping JavaScript links embedded in the portal's web pages. Due to insufficient sanitization, an attacker can craft malicious javascript: style links that bypass the escaping mechanism, allowing injection of arbitrary web scripts or HTML. This flaw enables remote attackers to execute scripts in the context of the victim's browser when they visit a compromised or maliciously crafted page on the vulnerable Liferay Portal instance. The vulnerability falls under CWE-79, which covers improper neutralization of input leading to XSS. Although no known exploits are currently reported in the wild, the vulnerability is publicly disclosed and affects multiple actively used versions of Liferay Portal, a widely deployed enterprise web platform used for building corporate intranets, websites, and portals. Exploitation requires no authentication and can be triggered remotely via crafted URLs or content that includes malicious javascript: links. The impact includes potential theft of user credentials, session hijacking, unauthorized actions on behalf of users, and delivery of further malware or phishing content through the portal interface. The vulnerability's medium severity reflects the moderate complexity of exploitation and the scope limited to web interface users, but it remains a significant risk due to the portal's role in enterprise environments and the sensitive information it may expose.

For European organizations using Liferay Portal, this XSS vulnerability poses risks to confidentiality, integrity, and availability of web-based services. Attackers could leverage the flaw to hijack user sessions, steal authentication tokens, or perform actions with the privileges of authenticated users, potentially leading to unauthorized data access or modification. Given Liferay's use in government, financial, healthcare, and large enterprise sectors across Europe, exploitation could result in exposure of sensitive personal data protected under GDPR, causing regulatory and reputational damage. Additionally, the vulnerability could be used as a vector for delivering malware or phishing campaigns targeting employees or customers, increasing the risk of broader compromise. The medium severity suggests that while the vulnerability is not trivially exploitable at scale without user interaction, targeted attacks against high-value portals are plausible. The lack of authentication requirement lowers the barrier for attackers to attempt exploitation. The impact is amplified in environments where Liferay portals integrate with internal systems or provide access to critical services, potentially enabling lateral movement or privilege escalation within organizational networks.

To mitigate CVE-2024-25147, European organizations should prioritize upgrading affected Liferay Portal instances to the latest patched versions or service/fix packs where the vulnerability is addressed. In the absence of immediate patches, organizations should implement strict input validation and output encoding on all user-supplied data, especially for URL parameters and content that may be rendered as JavaScript links. Web application firewalls (WAFs) can be configured with custom rules to detect and block requests containing suspicious javascript: style links or payloads indicative of XSS attempts. Additionally, organizations should enforce Content Security Policy (CSP) headers to restrict execution of inline scripts and untrusted sources, reducing the impact of potential XSS exploitation. Regular security audits and penetration testing focused on web application vulnerabilities should be conducted to identify residual risks. User awareness training about phishing and suspicious links can help reduce the success of social engineering attacks leveraging this vulnerability. Finally, monitoring portal logs for unusual or malformed requests can aid in early detection of exploitation attempts.