CVE-2025-43738 Overview
CVE-2025-43738 is a reflected cross-site scripting (XSS) vulnerability affecting Liferay Portal and Liferay Digital Experience Platform (DXP). The flaw resides in the _com_liferay_expando_web_portlet_ExpandoPortlet_displayType parameter of the Expando portlet. A remote authenticated user can inject arbitrary JavaScript that executes in the browser context of any victim who visits a crafted URL. The issue is classified under CWE-79: Improper Neutralization of Input During Web Page Generation. Successful exploitation enables session data theft, unauthorized actions on behalf of the victim, and further pivot into administrative functionality when higher-privileged users are targeted.
Critical Impact
Authenticated attackers can execute arbitrary JavaScript in a victim's browser session, enabling credential theft, session hijacking, and unauthorized actions within Liferay Portal or DXP.
Affected Products
- Liferay Portal 7.4.0 through 7.4.3.132
- Liferay DXP 2025.Q2.0 through 2025.Q2.8, 2025.Q1.0 through 2025.Q1.15, 2024.Q4.0 through 2024.Q4.7
- Liferay DXP 2024.Q3.1 through 2024.Q3.13, 2024.Q2.1 through 2024.Q2.13, 2024.Q1.1 through 2024.Q1.19
Discovery Timeline
- 2025-08-19 - CVE-2025-43738 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-43738
Vulnerability Analysis
The vulnerability exists in the Expando portlet, a Liferay component used to manage custom fields on portal entities. The displayType request parameter, prefixed with the portlet namespace _com_liferay_expando_web_portlet_ExpandoPortlet_, is reflected back into the rendered HTML without proper output encoding. Any authenticated user with access to a page hosting the Expando portlet can craft a URL that embeds JavaScript payloads through this parameter. When a victim follows the link, the injected script executes with the victim's session privileges. Because the payload runs inside the Liferay origin, it has access to session cookies, DOM contents, and any authenticated API endpoints accessible to that user.
Root Cause
The root cause is missing or insufficient contextual output encoding of the displayType parameter before it is embedded in the portlet's rendered HTML response. Reflected XSS defects of this class typically occur when a servlet or JSP writes untrusted request data directly into markup without HTML entity encoding or JavaScript escaping.
Attack Vector
Exploitation requires the attacker to hold valid Liferay credentials and to convince a target user to interact with a crafted link, matching the authenticated network vector with user interaction required. The attacker builds a URL targeting a page containing the Expando portlet and appends a malicious _com_liferay_expando_web_portlet_ExpandoPortlet_displayType value containing JavaScript. Delivery typically occurs through phishing, internal messaging, or embedded links in portal content. Targeting privileged accounts amplifies impact by enabling actions such as user creation, permission changes, or content modification through the portal's administrative interface.
No public proof-of-concept exploit was referenced in the advisory. Refer to the Liferay Security Advisory CVE-2025-43738 for vendor-supplied technical details.
Detection Methods for CVE-2025-43738
Indicators of Compromise
- HTTP requests containing the parameter _com_liferay_expando_web_portlet_ExpandoPortlet_displayType with values including <script, javascript:, onerror=, onload=, or URL-encoded equivalents such as %3Cscript.
- Referer headers pointing to external or untrusted domains preceding Expando portlet page loads.
- Unusual outbound requests from authenticated user browsers to attacker-controlled hosts shortly after clicking internal portal links.
Detection Strategies
- Inspect web server and reverse proxy access logs for query strings containing the vulnerable parameter with HTML or script metacharacters.
- Deploy WAF signatures that flag XSS payload patterns in Liferay portlet namespace parameters.
- Correlate authenticated Liferay session activity with anomalous outbound DOM-originated network traffic.
Monitoring Recommendations
- Enable verbose access logging on Liferay front-end web tiers and forward logs to a centralized analytics platform for query.
- Alert on repeated requests to Expando portlet URLs originating from the same authenticated account within short time windows.
- Track administrative actions performed immediately after Expando portlet page loads to catch session-riding follow-on activity.
How to Mitigate CVE-2025-43738
Immediate Actions Required
- Apply the security fixes referenced in the Liferay Security Advisory CVE-2025-43738 to all affected Portal 7.4 and DXP quarterly release branches.
- Inventory portal instances and verify whether the Expando portlet is deployed on user-accessible pages.
- Force session termination for accounts suspected of clicking crafted URLs and rotate any credentials handled through the portal.
Patch Information
Liferay has published fixes through its security advisory portal for all affected Portal 7.4.x and DXP quarterly releases. Customers on Liferay DXP should upgrade to the latest patched service pack within their supported quarterly release track. Portal 7.4 users should move to a version later than 7.4.3.132 or apply the corresponding fix pack. Consult the vendor advisory for exact fix pack identifiers and download instructions.
Workarounds
- Restrict access to pages hosting the Expando portlet to trusted administrative users only.
- Deploy a web application firewall rule that blocks or sanitizes requests containing script tags or JavaScript event handlers in the _com_liferay_expando_web_portlet_ExpandoPortlet_displayType parameter.
- Enforce a strict Content Security Policy (CSP) that disallows inline script execution to reduce the impact of reflected payloads.
- Educate authenticated portal users about phishing links that target internal portal URLs.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.