CVE-2022-36023 is a vulnerability classified under CWE-20 (Improper Input Validation) affecting Hyperledger Fabric, an enterprise-grade permissioned distributed ledger framework widely used for blockchain solutions and applications. The vulnerability arises when a gateway client application sends a malformed request to a gateway peer node. In versions of Hyperledger Fabric prior to 2.4.6, this malformed input is not properly validated, which can cause the peer node to crash. This denial-of-service (DoS) condition disrupts the availability of the peer node, potentially impacting the blockchain network's operation and reliability. The issue was addressed in version 2.4.6, where the software now detects malformed gateway requests and returns an error to the client instead of crashing. There are no known workarounds other than upgrading to the fixed version. No exploits have been observed in the wild to date, but the vulnerability represents a risk to network stability if exploited. The vulnerability does not require authentication or user interaction beyond sending a malformed request, which could be crafted by an internal or external actor with network access to the gateway peer. The scope is limited to Hyperledger Fabric deployments running versions earlier than 2.4.6, specifically affecting the gateway peer nodes that process client requests. Given the critical role of peer nodes in maintaining ledger consistency and transaction validation, a crash can degrade network availability and trustworthiness.

For European organizations utilizing Hyperledger Fabric in their blockchain infrastructures, this vulnerability poses a risk primarily to availability. A successful exploitation can cause peer nodes to crash, leading to service interruptions, transaction processing delays, and potential loss of business continuity in blockchain-based applications. Industries relying on blockchain for supply chain management, finance, healthcare, or government services could face operational disruptions. Additionally, repeated crashes could undermine confidence in the blockchain network's reliability and integrity. Although the vulnerability does not directly compromise confidentiality or data integrity, the denial-of-service impact can indirectly affect business operations and compliance with service-level agreements. European organizations with critical blockchain deployments must consider the potential cascading effects on interconnected systems and partners. The lack of known exploits reduces immediate risk, but the ease of triggering the crash via malformed requests means that attackers with network access could exploit this vulnerability to disrupt services.

The primary and only effective mitigation is to upgrade all Hyperledger Fabric deployments to version 2.4.6 or later, where the input validation flaw has been fixed. Organizations should implement a rigorous patch management process to ensure timely updates. Additionally, network segmentation and strict access controls should be enforced to limit which clients can send requests to gateway peers, reducing exposure to potentially malicious malformed requests. Deploying application-layer firewalls or input validation proxies that can detect and block malformed requests before they reach the peer nodes can provide an additional protective layer. Monitoring peer node health and setting up automated alerts for crashes or abnormal behavior will enable rapid response to potential exploitation attempts. Finally, organizations should review and test their incident response plans to handle potential denial-of-service events impacting blockchain infrastructure.