CVE-2026-52880 in klever-go
Summary
by MITRE • 08/08/2026
Klever-Go is the Go implementation of the Klever blockchain protocol. Versions from 1.7.14 through 1.7.17 are vulnerable to a remotely triggerable denial of service. Both REST APIs are started with the Gin Engine.Run convenience method, which serves requests through Go's default HTTP server with no ReadHeaderTimeout, ReadTimeout, or MaxHeaderBytes configured. As a result, incoming connections that never complete their request headers are held open indefinitely. When a REST listener is reachable beyond localhost through the documented all-interface bind or a Docker port-publish deployment, a single unauthenticated client can open many slow-header connections and hold them open until server file descriptors are exhausted, preventing the API from accepting new connections. This renders the REST API unavailable to legitimate clients. This issue is fixed in version 1.7.18.
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Analysis
by VulDB Data Team • 08/08/2026
The Klever-Go blockchain implementation presents a critical denial of service vulnerability affecting versions 1.7.14 through 1.7.17, where the REST API endpoints become completely unresponsive due to inadequate HTTP server configuration. This flaw stems from the application's reliance on Gin Engine.Run convenience method which initializes Go's default HTTP server without proper timeout and resource limiting parameters. The vulnerability operates through a straightforward yet effective mechanism where malicious actors can establish multiple TCP connections that never complete their HTTP request headers, thereby maintaining open file descriptors indefinitely.
The technical implementation of this vulnerability lies in the absence of fundamental HTTP server security configurations within the application's network stack. When REST listeners bind to all interfaces or are exposed via Docker port publishing mechanisms, they become accessible beyond localhost boundaries and vulnerable to exploitation. The default Go HTTP server configuration lacks ReadHeaderTimeout, ReadTimeout, and MaxHeaderBytes parameters that would normally prevent resource exhaustion attacks. This configuration creates a scenario where attackers can maintain persistent connections without completing the HTTP request handshake process, effectively consuming available file descriptors on the server.
The operational impact of this vulnerability extends beyond simple service disruption to create a complete denial of service condition for legitimate users. An unauthenticated client can establish numerous slow-header connections that remain open indefinitely until the server's file descriptor limit is reached. Once resource exhaustion occurs, the API becomes completely unavailable to all clients including legitimate ones, creating a cascading failure effect that prevents normal blockchain operations and user interactions. This vulnerability directly maps to CWE-400 weakness category related to resource exhaustion and represents a classic example of insufficient timeout handling in network services.
The exploitation pattern demonstrates characteristics aligned with ATT&CK technique T1499.004 for network denial of service attacks, where adversaries leverage protocol-level weaknesses to exhaust system resources. The vulnerability affects both REST API endpoints simultaneously since they share the same underlying HTTP server configuration, making mitigation more complex as it requires addressing the root cause rather than individual endpoint configurations. Network administrators and security teams deploying Klever-Go versions within this affected range face significant operational risks when these services are exposed externally, as even a single malicious actor can render the entire API unavailable.
The fix implemented in version 1.7.18 addresses this issue by properly configuring HTTP server timeouts and resource limits through appropriate initialization parameters. This remediation follows established security best practices for preventing resource exhaustion attacks and aligns with industry standards for secure network service development. The solution demonstrates the importance of proper timeout configuration in web applications and highlights how default configurations in popular frameworks can create significant security vulnerabilities when deployed in production environments without proper security hardening measures.