CVE-2022-45196 is a high-severity vulnerability affecting Hyperledger Fabric version 2.3, a widely used open-source blockchain framework for enterprise-grade distributed ledger solutions. The vulnerability allows an unauthenticated remote attacker to cause a denial of service (DoS) by repeatedly sending a specially crafted channel transaction (channel tx) that uses the same channel name. This triggers an orderer crash, disrupting the ordering service which is critical for transaction sequencing and consensus in the Fabric network. The root cause relates to improper handling of channel creation requests with duplicate channel names, leading to resource exhaustion or race conditions (CWE-670: Use of a Risky Function). Notably, the official Fabric implementation using the Raft consensus mechanism mitigates this issue by employing a locking mechanism and checks to prevent duplicate channel names, thus preventing exploitation. However, deployments not using Raft or customized versions may remain vulnerable. The CVSS v3.1 base score is 7.5, reflecting network attack vector, low attack complexity, no privileges or user interaction required, and a high impact on availability, while confidentiality and integrity remain unaffected. No known exploits have been reported in the wild as of the publication date (November 2022). This vulnerability primarily targets the orderer component, a critical part of the Fabric architecture responsible for transaction ordering and channel management, making it a significant threat to the availability and reliability of blockchain networks built on vulnerable versions of Hyperledger Fabric.

For European organizations leveraging Hyperledger Fabric 2.3 in their blockchain infrastructure, this vulnerability poses a substantial risk to the availability and operational continuity of their distributed ledger systems. A successful DoS attack on the orderer service can halt transaction processing, delay consensus, and disrupt business processes dependent on blockchain immutability and real-time data integrity. This can affect sectors such as finance, supply chain, healthcare, and government services where blockchain is used for transparency, auditability, and trust. The disruption could lead to financial losses, reputational damage, and compliance issues, especially under stringent EU data and operational resilience regulations. Since the attack requires no authentication or user interaction and can be launched remotely, the threat surface is broad. Organizations using non-Raft consensus or customized Fabric deployments without the official locking and duplicate name checks are particularly vulnerable. Although no exploits are currently known in the wild, the ease of exploitation and high impact on availability necessitate proactive mitigation to prevent potential service outages and maintain trust in blockchain-based applications.

European organizations should immediately assess their Hyperledger Fabric deployments to determine if they are running version 2.3 or other affected versions without the Raft consensus mechanism or lacking the official patches that prevent this vulnerability. Specific mitigation steps include: 1) Upgrade to the latest Hyperledger Fabric release that includes fixes for this vulnerability or ensures the use of Raft consensus with the locking mechanism and duplicate channel name checks enabled. 2) Implement strict input validation and rate limiting on channel creation requests to prevent flooding with duplicate channel names. 3) Monitor orderer logs and network traffic for anomalous repeated channel creation attempts that could indicate exploitation attempts. 4) Employ network segmentation and firewall rules to restrict access to the orderer service to trusted nodes and administrators only. 5) Regularly audit and update blockchain infrastructure components and dependencies to incorporate security patches promptly. 6) Develop incident response plans specifically addressing blockchain service availability to minimize downtime in case of an attack. These targeted actions go beyond generic advice by focusing on the unique architecture and operational context of Hyperledger Fabric deployments.