CVE-2025-43763 is a Server-Side Request Forgery (SSRF) vulnerability identified in Liferay Portal versions 7.4.0 through 7.4.3.131 and multiple versions of Liferay DXP from 2024.Q1.1 through 2024.Q4.7. The vulnerability specifically affects custom object attachment fields within these products. SSRF vulnerabilities occur when an attacker can manipulate a server to make unauthorized requests to internal or external resources, potentially bypassing network restrictions or accessing sensitive internal services. In this case, the flaw allows an attacker to craft requests that cause the Liferay Portal to generate new object entries linking to external resources controlled or specified by the attacker. This can lead to unauthorized internal network scanning, data exfiltration, or interaction with internal services that are otherwise inaccessible externally. The vulnerability requires some level of privileges (PR:H) and user interaction (UI:P), indicating that an attacker must have some authenticated access and potentially trick a user into triggering the exploit. The CVSS 4.0 score is 4.8 (medium severity), reflecting limited confidentiality and integrity impact with no direct availability impact, and low complexity to exploit once privileges are obtained. No known exploits are currently reported in the wild, and no patches have been linked yet, suggesting that mitigation may rely on configuration or access control until official fixes are released.

For European organizations using Liferay Portal or Liferay DXP, this SSRF vulnerability poses a moderate risk. Liferay is widely used in enterprise content management, intranet portals, and customer-facing web applications, including in government, education, and private sectors across Europe. Exploitation could allow attackers with some authenticated access to pivot into internal networks, access sensitive internal services, or exfiltrate data by abusing the server's ability to make arbitrary HTTP requests. This could lead to unauthorized data disclosure or lateral movement within corporate networks. The impact is particularly significant for organizations with strict network segmentation relying on Liferay as a gateway or integration point. However, the requirement for authenticated access and user interaction limits the attack surface to insiders or targeted phishing campaigns. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once patches are available.

European organizations should implement the following specific mitigations: 1) Restrict and monitor user privileges within Liferay Portal to minimize the number of users who can create or modify custom object attachment fields. 2) Apply strict input validation and sanitization on any user-supplied URLs or external resource references in custom object attachments to prevent malicious request injection. 3) Implement network-level egress filtering to restrict the Liferay server's outbound HTTP requests to only trusted destinations, blocking unauthorized internal or external calls. 4) Monitor logs for unusual outbound requests originating from Liferay Portal instances, especially those targeting internal IP ranges or unexpected external domains. 5) Educate users about phishing and social engineering risks to reduce the chance of triggering the vulnerability via user interaction. 6) Stay alert for official patches or updates from Liferay and apply them promptly once available. 7) Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block SSRF patterns targeting Liferay endpoints. These targeted mitigations go beyond generic advice by focusing on privilege management, network controls, and monitoring tailored to the nature of this SSRF vulnerability.