CVE-2025-64408 is a deserialization vulnerability classified under CWE-502 affecting Apache Causeway, an open-source framework by the Apache Software Foundation used for building domain-driven applications in Java. The vulnerability stems from unsafe deserialization of untrusted data passed via URL parameters to the ViewModel functionality. This flaw allows authenticated attackers to craft malicious serialized objects that, when deserialized by the application, lead to remote code execution (RCE) with the privileges of the application process. The vulnerability impacts all versions prior to 3.5.0, including 2.0.0 and 4.0.0-M1. The attack vector is network-based (AV:N), requires low attack complexity (AC:L), but does require privileges (PR:L) and no user interaction (UI:N). The scope is unchanged (S:U), and the impact affects confidentiality, integrity, and availability to a limited extent (C:L/I:L/A:L). The vulnerability is significant because deserialization flaws can allow attackers to bypass security controls and execute arbitrary code, potentially leading to full system compromise depending on the deployment context. No public exploits have been reported yet, but the presence of the vulnerability in widely used versions means organizations should act quickly. The fix is available in Apache Causeway version 3.5.0, which addresses the unsafe deserialization by implementing safer deserialization practices or input validation.

For European organizations, the vulnerability poses a risk of remote code execution within applications using Apache Causeway's ViewModel functionality. This can lead to unauthorized access, data leakage, manipulation, or service disruption. Since exploitation requires authentication, insider threats or compromised credentials increase risk. The impact on confidentiality, integrity, and availability, although rated low to medium, can escalate depending on the application's role and privileges. Organizations in sectors such as government, finance, and critical infrastructure that use Apache Causeway for internal or customer-facing applications could face operational disruptions or data breaches. The medium CVSS score reflects the balance between required authentication and the severity of RCE. The absence of known exploits reduces immediate risk but does not eliminate it, especially as attackers may develop exploits over time. Failure to patch could lead to targeted attacks, especially in environments with weak credential management or exposed administrative interfaces.

European organizations should immediately inventory all applications using Apache Causeway, focusing on those employing the ViewModel functionality. The primary mitigation is upgrading all affected instances to Apache Causeway version 3.5.0 or later, which contains the fix for this vulnerability. Where immediate upgrade is not possible, organizations should restrict access to affected applications to trusted users only, enforce strong authentication and authorization controls, and monitor logs for suspicious deserialization activity or anomalous behavior. Implement network segmentation to limit exposure of vulnerable services. Additionally, applying runtime application self-protection (RASP) or web application firewalls (WAF) with rules to detect and block malicious serialized payloads can provide temporary defense. Developers should review and refactor code to avoid unsafe deserialization patterns and validate or sanitize all user inputs, especially those influencing deserialization. Regular security assessments and penetration testing focused on deserialization vulnerabilities are recommended to identify residual risks.