Client Overview
The client is a leading financial institution participating in one of the world’s most ambitious central bank digital currency (CBDC) pilot programs. Operating blockchain validator nodes alongside enterprise-grade infrastructure, the institution plays a critical role in a nationally significant distributed ledger network designed to modernize interbank settlement and digital payments. With regulatory scrutiny and institutional counterparties depending on the integrity of this infrastructure, the security stakes extended well beyond the organization itself.
Key Security Challenges
The institution was operating blockchain validator nodes within a high-profile, government-backed DLT network where a single compromised node could undermine consensus integrity and erode trust across the entire ecosystem.
Enterprise IT infrastructure, including Active Directory, identity management, and network devices, was tightly integrated with blockchain operations, creating a complex attack surface that spanned both traditional and decentralized environments.
As a participant in a multi-party CBDC pilot, the client needed independent validation that its infrastructure met the security standards expected by regulators, central bank counterparts, and institutional peers before advancing to later pilot phases.
Halborn’s Solutions
Red Team Exercise: Conducted a full-scope adversarial simulation across the client’s blockchain and enterprise infrastructure, emulating real-world threat actors to identify exploitable weaknesses before an attacker could.
Infrastructure Penetration Testing: Assessed the security posture of the Windows domain environment, Active Directory, network devices, and shared resources that underpinned the client’s blockchain operations.
Blockchain Node Security Assessment: Evaluated the configuration, access controls, and exposure of Hyperledger Besu validator nodes running QBFT consensus, focusing on JSON-RPC interfaces, peer management, and consensus integrity.
Identity and Access Management Review: Analyzed Kerberos authentication, password policies, LAPS configurations, and privilege escalation paths across the domain environment.
Assets and Technologies Assessed
Hyperledger Besu validator and full nodes (QBFT consensus)
JSON-RPC endpoints (HTTP and WebSocket) across multiple administrative namespaces
Active Directory domain infrastructure, Kerberos authentication, and LAPS
Network devices including routers, switches, and firewalls (configuration review)
Shared file systems, private key storage, and sensitive data repositories
Volume Shadow Copy Service (VSS) and backup infrastructure
Results Achieved
Identified 16 vulnerabilities across the infrastructure, including 4 critical and 9 high-severity findings, providing the client with a complete picture of exploitable weaknesses before any adversary could discover them.
Uncovered unauthenticated access to administrative blockchain APIs that could have allowed an external actor to inject or remove peers from the consensus network, directly threatening the integrity of the CBDC pilot.
Exposed critical credential and identity weaknesses, including guessable passwords, weak password policies, and Kerberoastable service accounts, that created lateral movement and privilege escalation paths across the domain.
Delivered a prioritized remediation roadmap with CVSS-scored findings and actionable, implementation-ready recommendations tailored to both blockchain node hardening and enterprise infrastructure controls.
What Set Halborn Apart
This engagement demanded a rare combination of expertise: the ability to conduct adversarial operations against enterprise Active Directory and Windows infrastructure while simultaneously understanding the nuances of blockchain consensus protocols, JSON-RPC security, and validator node architecture. Halborn’s team brought both disciplines under one roof, eliminating the need for the client to coordinate between a traditional penetration testing firm and a blockchain-specific auditor.
Halborn’s methodology treated the blockchain and enterprise layers as a unified attack surface, not as siloed assessments. This approach revealed critical cross-domain attack paths, such as using compromised Active Directory credentials to access shared folders containing private keys, or leveraging weak password policies to pivot from the corporate domain into blockchain node management interfaces. These compound risk chains would have been invisible to assessors examining either layer in isolation.
Going Above and Beyond
More than a point-in-time security assessment, Halborn’s engagement served as a strategic inflection point for the client’s participation in the CBDC pilot. By mapping the full adversarial landscape across both enterprise and blockchain infrastructure, Halborn gave the client’s security, engineering, and compliance teams a shared understanding of where their most critical exposures lay, and a clear path to closing them.
The findings extended beyond individual vulnerabilities to reveal systemic patterns: overly permissive RPC configurations across multiple nodes, inconsistent access controls on sensitive shared resources, and identity infrastructure that had not been hardened for the elevated threat model of a nationally significant DLT network. Halborn’s recommendations addressed these root causes, not just their symptoms, positioning the client to implement durable security improvements rather than one-off patches.
By completing this engagement, the client was positioned to advance confidently into subsequent phases of the CBDC pilot, with independently validated infrastructure, a strengthened security posture, and the documentation needed to demonstrate operational resilience to regulators, central bank partners, and institutional counterparties. Halborn continues to stand ready as a long-term security partner as the network evolves from pilot to production.
