CVE-2025-11374 is a vulnerability classified under CWE-770, which pertains to the allocation of resources without proper limits or throttling. Specifically, HashiCorp Consul's key/value HTTP endpoint incorrectly validates the Content-Length header in incoming requests. This improper validation allows an attacker to send requests that cause the server to allocate excessive resources, leading to denial of service by exhausting memory or processing capacity. The attack vector is network-based (AV:N), requires low privileges (PR:L), and does not require user interaction (UI:N). The vulnerability affects multiple versions of Consul prior to the patched releases. The CVSS v3.1 base score is 6.5, indicating a medium severity primarily due to the impact on availability (A:H) without affecting confidentiality or integrity. The scope remains unchanged (S:U), meaning the impact is limited to the vulnerable component. The vulnerability does not require authentication to exploit but does require the attacker to have network access to the Consul key/value endpoint. HashiCorp has released fixes in several versions, emphasizing the importance of upgrading to these patched versions to mitigate the risk. No public exploits or active exploitation have been reported, but the nature of the vulnerability makes it a potential vector for service disruption in environments relying on Consul for critical infrastructure services.

For European organizations, the primary impact of CVE-2025-11374 is the potential for denial of service attacks that disrupt service discovery, configuration management, and other critical functions managed by HashiCorp Consul. This can lead to downtime, degraded performance, and operational disruptions in cloud-native environments, microservices architectures, and DevOps pipelines. Organizations in sectors such as finance, telecommunications, and government, which rely heavily on Consul for infrastructure automation and service orchestration, may experience significant operational impact. The disruption could affect business continuity and service level agreements, potentially leading to financial losses and reputational damage. Since the vulnerability does not compromise data confidentiality or integrity, the risk is primarily operational. However, prolonged outages could indirectly affect security monitoring and incident response capabilities. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits targeting unpatched systems.

1. Upgrade Consul to the fixed versions: Community Edition 1.22.0 or Enterprise versions 1.22.0, 1.21.6, 1.20.8, or 1.18.12 as soon as possible. 2. Implement network segmentation and firewall rules to restrict access to Consul key/value endpoints only to trusted hosts and services. 3. Monitor network traffic for unusual or excessive requests targeting the key/value endpoint, focusing on anomalous Content-Length header values or request patterns. 4. Employ rate limiting or request throttling mechanisms at the network or application layer to prevent resource exhaustion attacks. 5. Conduct regular vulnerability scans and penetration tests to detect unpatched instances of Consul. 6. Review and harden Consul configuration to minimize exposure of sensitive endpoints. 7. Maintain an incident response plan that includes procedures for mitigating DoS attacks affecting service discovery infrastructure. These steps go beyond generic advice by emphasizing proactive monitoring, network controls, and configuration hardening tailored to Consul deployments.