CVE-2025-41253 is an Expression Language Injection vulnerability (CWE-917) found in VMware's Spring Cloud Gateway Server Webflux component, specifically affecting versions 3.1.x through 4.3.x. The vulnerability occurs when the Spring Cloud Gateway actuator web endpoints are enabled and exposed to untrusted users without adequate security controls. These actuator endpoints, when enabled via configuration properties such as management.endpoints.web.exposure.include=gateway and management.endpoint.gateway.enabled=true or management.endpoint.gateway.access=unrestricted, allow an attacker to create or manipulate routes that use Spring Expression Language (SpEL). SpEL is a powerful expression language used within Spring applications to dynamically evaluate expressions, including accessing environment variables and system properties. If an attacker can inject SpEL expressions through route definitions, they can extract sensitive information such as environment variables and system properties, which may contain credentials, configuration secrets, or other sensitive data. The vulnerability requires no authentication (PR:N) and no user interaction (UI:N), and can be exploited remotely over the network (AV:N). The CVSS v3.1 base score is 7.5, indicating a high severity primarily due to the confidentiality impact (C:H) without affecting integrity or availability. The vulnerability does not affect Spring Cloud Gateway Server WebMVC, only the Webflux variant. No public exploits have been reported yet, but the risk is significant given the ease of exploitation and potential data exposure. The root cause is improper neutralization of special elements in SpEL expressions, allowing injection attacks. This vulnerability highlights the importance of securing actuator endpoints and controlling route creation privileges in Spring Cloud Gateway deployments.

For European organizations, this vulnerability poses a significant risk to confidentiality, as attackers can remotely extract sensitive environment variables and system properties without authentication or user interaction. Organizations relying on Spring Cloud Gateway Server Webflux in critical applications, especially those exposing actuator endpoints for monitoring or management, may inadvertently expose secrets such as database credentials, API keys, or internal configuration details. This can lead to further compromise, including lateral movement or data breaches. The impact is particularly severe for sectors with stringent data protection requirements such as finance, healthcare, and government. Additionally, organizations using cloud-native or microservices architectures that leverage Spring Cloud Gateway for API routing and management are at heightened risk. The vulnerability does not directly affect system integrity or availability, but the confidentiality breach can have cascading effects on overall security posture and compliance with regulations like GDPR. The absence of known exploits in the wild provides a window for proactive mitigation, but the ease of exploitation and high impact necessitate urgent attention.

1. Immediately review and restrict access to Spring Cloud Gateway actuator endpoints. Disable the gateway actuator endpoint if not required by setting management.endpoint.gateway.enabled=false or removing 'gateway' from management.endpoints.web.exposure.include. 2. If actuator endpoints must be enabled, enforce strict authentication and authorization controls to prevent untrusted third parties from accessing or modifying routes. 3. Limit the ability to create or modify routes to trusted administrators only, preventing untrusted users from injecting malicious SpEL expressions. 4. Monitor logs and network traffic for unusual requests targeting actuator endpoints or route creation APIs. 5. Apply vendor patches or updates as soon as they become available to address this vulnerability. 6. Conduct a thorough audit of environment variables and system properties to identify and minimize sensitive information exposure. 7. Employ network segmentation and firewall rules to restrict access to management endpoints from untrusted networks. 8. Educate development and operations teams about the risks of enabling actuator endpoints without proper security controls. 9. Consider implementing runtime application self-protection (RASP) or Web Application Firewalls (WAF) with rules to detect and block suspicious SpEL injection attempts. 10. Regularly review and update security configurations in line with best practices for Spring Cloud Gateway deployments.