CVE-2025-13805 identifies a deserialization vulnerability in the NutzBoot framework, version 2.6.0-SNAPSHOT and earlier, specifically within the LiteRpc-Serializer component's getInputStream function located in the HttpServletRpcEndpoint.java file. The vulnerability arises from insufficient validation or sanitization of serialized input data, allowing an attacker to manipulate the deserialization process remotely. Deserialization flaws can lead to arbitrary code execution, data leakage, or denial of service depending on the payload and context. In this case, the attack vector is network-based, requiring no authentication or user interaction, but the complexity of crafting a successful exploit is high, and exploitability is difficult. The CVSS 4.0 score of 6.3 reflects medium severity, with network attack vector (AV:N), high attack complexity (AC:H), and no privileges or user interaction required. The impact on confidentiality is low, with no direct impact on integrity or availability reported. Although no active exploits are currently observed in the wild, publicly available exploit code increases the risk of future attacks. NutzBoot is a Java-based framework used in enterprise applications, and the vulnerable component handles RPC calls over HTTP, making exposed endpoints potential targets. The lack of vendor patches at the time of publication necessitates immediate defensive measures to mitigate risk. This vulnerability underscores the critical need for secure deserialization practices and input validation in RPC frameworks.

For European organizations, the vulnerability poses a moderate risk primarily to confidentiality due to potential unauthorized data access via manipulated deserialization. While the integrity and availability impacts are minimal, successful exploitation could enable attackers to execute arbitrary code or escalate privileges in some scenarios, especially if combined with other vulnerabilities. Organizations relying on NutzBoot for internal or external services, particularly those exposing RPC endpoints over HTTP, could face targeted attacks aiming to compromise sensitive data or disrupt services. The medium severity and high complexity reduce the likelihood of widespread exploitation but do not eliminate risk, especially for high-value targets. The presence of publicly available exploit code increases the threat landscape, potentially attracting skilled attackers. European entities in sectors such as finance, telecommunications, and government, which often use Java-based frameworks and RPC mechanisms, may be particularly concerned. Additionally, supply chain risks exist if third-party software integrates vulnerable NutzBoot versions. Overall, the impact is significant enough to warrant proactive mitigation to protect confidentiality and prevent potential escalation.

1. Monitor for and apply official patches or updates from the Nutzam project as soon as they become available. 2. Restrict network access to the vulnerable RPC endpoints by implementing firewall rules and network segmentation to limit exposure to untrusted networks. 3. Employ strict input validation and sanitization on all serialized data received by the LiteRpc-Serializer component to prevent malicious payloads. 4. Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block suspicious deserialization patterns or malformed RPC requests. 5. Conduct code audits and penetration testing focused on deserialization and RPC mechanisms to identify and remediate similar weaknesses. 6. Use runtime application self-protection (RASP) tools to detect and prevent exploitation attempts in real time. 7. Educate developers and security teams about secure deserialization practices and the risks associated with unsafe deserialization. 8. Implement logging and monitoring to detect anomalous RPC endpoint activity that could indicate exploitation attempts. 9. If immediate patching is not possible, consider disabling or isolating the vulnerable component temporarily. 10. Review and update incident response plans to include scenarios involving deserialization attacks.