CVE-2025-53602 is a medium-severity vulnerability affecting Open Zipkin, specifically versions up to 3.5.1. Zipkin is a distributed tracing system commonly used to monitor and troubleshoot microservices architectures. The vulnerability is related to the presence of a /heapdump endpoint, which is exposed through the Spring Boot Actuator integration. This endpoint allows access to heap dumps, which contain detailed runtime memory information of the Java process. The issue is classified under CWE-1188, indicating that a resource is initialized with insecure default settings. In this case, the /heapdump endpoint is enabled or accessible by default without proper authentication or access controls, potentially exposing sensitive application memory data. The CVSS v3.1 base score is 5.3, reflecting a network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), limited confidentiality impact (C:L), and no impact on integrity or availability (I:N/A:N). This means an unauthenticated attacker can remotely access the heap dump data, which may contain sensitive information such as credentials, tokens, or internal application state, but cannot modify or disrupt the system directly. The vulnerability is similar to CVE-2025-48927, which also involved insecure exposure of Spring Boot Actuator endpoints. No known exploits are currently reported in the wild, and no official patches or mitigations have been linked yet. However, the presence of this endpoint in production environments without proper security controls poses a risk of information disclosure that could facilitate further attacks.

For European organizations, the exposure of the /heapdump endpoint in Zipkin instances can lead to unauthorized disclosure of sensitive runtime data. This can compromise confidentiality by leaking credentials, tokens, or proprietary application logic, potentially enabling attackers to escalate privileges or move laterally within the network. Organizations relying on Zipkin for monitoring microservices, especially in sectors like finance, healthcare, and critical infrastructure, may face increased risk of data breaches or compliance violations under GDPR due to unauthorized access to sensitive information. Although the vulnerability does not directly affect system integrity or availability, the information gained could be leveraged in multi-stage attacks. Given the widespread adoption of Spring Boot and Zipkin in European enterprises, particularly in Germany, France, the UK, and the Netherlands, the impact could be significant if not mitigated. The lack of authentication requirements and the network-exposed nature of the endpoint increase the attack surface. Additionally, the vulnerability could undermine trust in observability tools and complicate incident response efforts if attackers use heap dump data to evade detection.

European organizations should immediately audit their Zipkin deployments to identify if the /heapdump endpoint is enabled and accessible externally. Specific mitigation steps include: 1) Disable the /heapdump endpoint in Spring Boot Actuator configurations unless explicitly required for debugging in secure environments. 2) Restrict access to actuator endpoints using network-level controls such as firewalls, VPNs, or zero-trust segmentation to limit exposure to trusted administrators only. 3) Implement authentication and authorization mechanisms for all actuator endpoints, leveraging Spring Security or similar frameworks to enforce role-based access. 4) Regularly update Zipkin and Spring Boot dependencies to incorporate security patches once available. 5) Monitor logs and network traffic for unusual access patterns to actuator endpoints. 6) Conduct internal penetration testing and vulnerability scans focusing on observability infrastructure. 7) Educate development and operations teams about the risks of exposing debug endpoints in production. These steps go beyond generic advice by focusing on configuration hardening, access control, and proactive monitoring tailored to the Zipkin and Spring Boot ecosystem.