CVE-2025-48734 is an improper access control vulnerability classified under CWE-284 found in Apache Commons BeanUtils versions 1.x prior to 1.11.0 and 2.x prior to 2.0.0-M2. The vulnerability stems from the ability of an attacker to exploit the 'declaredClass' property of Java enum objects via the PropertyUtilsBean.getProperty() and getNestedProperty() methods. These methods allow property path expressions to be evaluated on Java objects, and if these paths are derived from untrusted external input, an attacker can access the enum's class loader by referencing the 'declaredClass' property. Access to the class loader enables the attacker to load arbitrary classes or execute arbitrary code remotely, leading to a critical remote code execution (RCE) scenario. The Apache Commons BeanUtils library introduced a special BeanIntrospector in version 1.9.2 to prevent this, but it was not enabled by default until versions 1.11.0 and 2.0.0-M2, where it suppresses access to the 'declaredClass' property by default. The vulnerability requires that the application uses BeanUtils to process property paths from external sources without validation or sanitization, making it a critical risk in web applications or services that dynamically evaluate Java bean properties. The CVSS v3.1 score of 8.8 reflects the network attack vector, low attack complexity, requirement for privileges but no user interaction, and high impact on confidentiality, integrity, and availability. No known exploits are currently reported in the wild, but the vulnerability is severe and warrants immediate remediation.

For European organizations, this vulnerability poses a significant risk of remote code execution in Java applications that utilize vulnerable versions of Apache Commons BeanUtils. Exploitation could lead to full system compromise, data breaches, unauthorized access to sensitive information, and disruption of services. Organizations in sectors such as finance, healthcare, government, and critical infrastructure that rely on Java-based enterprise applications are particularly at risk. The ability to execute arbitrary code remotely can facilitate lateral movement within networks, persistent access, and deployment of ransomware or other malware. Given the widespread use of Apache Commons libraries in Java ecosystems, the attack surface is broad. Failure to patch or mitigate this vulnerability could result in regulatory non-compliance under GDPR due to potential data breaches and operational disruptions. The impact extends to cloud-hosted Java applications and microservices architectures prevalent in European enterprises, increasing the urgency for remediation.

1. Upgrade all affected Apache Commons BeanUtils dependencies to version 1.11.0 or later for 1.x series, or 2.0.0-M2 or later for 2.x series, where the BeanIntrospector blocking 'declaredClass' access is enabled by default. 2. Audit all Java applications to identify usage of PropertyUtilsBean.getProperty() and getNestedProperty() methods, especially where property paths originate from external or untrusted sources. 3. Implement strict input validation and sanitization to prevent untrusted property paths from being passed to BeanUtils methods. 4. If upgrading is not immediately feasible, consider disabling or restricting the usage of BeanUtils in application code or applying custom BeanIntrospector configurations to block 'declaredClass' property access. 5. Employ runtime application self-protection (RASP) or Java security managers to limit class loader access and execution privileges. 6. Monitor application logs for suspicious property access patterns or unexpected class loader interactions. 7. Conduct penetration testing focused on property path injection to verify the effectiveness of mitigations. 8. Educate development teams about safe usage patterns of reflection and bean utilities to avoid similar vulnerabilities.