Keystore Vanguard Attack

Attack Description: The “Keystore Vanguard” attack exploits a vulnerability in Bitcoin Core’s benchmark code where private keys are stored in memory without being cleared after use. The attack takes its name from the military term “vanguard”—a forward unit that paves the way for the main force, just as this attack creates a springboard for extracting all generated cryptographic keys. wikipedia

The critical Keystore Vanguard vulnerability poses one of the most devastating threats to the Bitcoin ecosystem, exposing fundamental problems in private key management across hardware and software. This attack, classified as a Private Key Compromise Attack, bypasses cryptographic barriers and strikes at the very core of Bitcoin’s trust: with simple access to process memory, an attacker can silently and massively gain complete control over all generated private keys, leading to unlimited theft of funds, falsified transactions, and disruption of the decentralized infrastructure. christian-rossow+4

The Keystore Vanguard Attack demonstrates how a single flaw in the key lifecycle can turn any secure wallet into a source of catastrophic leakage of critical data—a danger so great that it can undermine not only individual services and wallets, but also the very idea of independent digital currencies. This attack vector requires immediate attention from experts and the implementation of strict key management security standards across all stages of the cryptoasset lifecycle. keyhunters+2

Attack mechanism

An attacker gains access to a structure keystore.keyscontaining all private keys generated during the benchmarking process. Each call keystore.keys.emplace(key_id, privkey)adds a new private key to persistent storage without automatic cleanup mechanisms. netwrix+2

Attack Vector: Persistent Storage of Cryptographic Secrets
Target line: keystore.keys.emplace(key_id, privkey);
Consequences: Complete compromise of all generated private keys
Operational complexity: Low (requires only access to process memory)

Technical specifics

The attack is particularly dangerous in the context of benchmark testing, where multiple keys are generated in a row. Unlike classic attacks on cryptographic primitives, Keystore Vanguard exploits an architectural vulnerability in the lifecycle management of secret data. cobalt+3

Keystore Vanguard: A Critical Vulnerability in Private Key Management and a Dangerous Attack on Bitcoin Cryptocurrency Security

Research paper: The Impact of the Keystore Vanguard Attack on Bitcoin Security

Cryptocurrencies like Bitcoin rely on private keys to authenticate transactions and protect user funds. A leaked private key would lead to a complete loss of control over digital assets and could trigger a large-scale attack on the Bitcoin ecosystem. christian-rossow+2

The nature of vulnerability

The architectural vulnerability in Keystore Vanguard arises from improper private key lifecycle management in the Bitcoin Core benchmark code. Private keys accumulate in a memory structure (keystore), remaining accessible even after signing operations are completed. Any attacker with access to the process or memory dump can extract the key material. keyhunters+2

The threat is realized through:

direct access to the process memory where private keys are stored;
attacks on debug interfaces, dumps and memory monitoring;
exploitation of OS vulnerabilities that allow for the theft of keys. publications.cispa+2

Scientific name of the attack

This attack is classified in the scientific literature as a Private Key Compromise Attack . This paper proposes a catchy name for the architectural implementation in Bitcoin Core: Keystore Vanguard Attack . This name emphasizes the strategic nature of the problem of managing key material in memory. cispa+4

CVE and vulnerability standardization

The Private Key Compromise attack category encompasses a wide range of implementations and does not have a single, universal CVE number. However, individual implementations of this vulnerability receive their own CVE identifiers. For example: keyhunters

CVE-2023-37192 is a memory management vulnerability in Bitcoin Core 22 that allows an attacker to modify and intercept sent addresses by accessing wiz+2 application memory.
CVE-2025-27840 is a vulnerability in hardware wallets that allows private key extraction via remote attacks on IoT devices. keyhunters

Impact of vulnerability on Bitcoin attack

Successful exploitation of the Keystore Vanguard Attack results in the following consequences:

Massive private key compromise : All generated private keys become available for extraction, allowing the attacker to sign any transactions on behalf of the victim. christian-rossow+2
Theft of funds : control over accounts is lost, and any funds can be transferred to the attacker’s addresses.
Forcing fake transactions and double spending – signing fake or duplicate transactions, threatening the trust in the system.
Scalability attacks : A massive key compromise could lead to a cascading loss of trust in the ecosystem and the collapse of entire services.

Real-life cases of two-week compromises resulted in the loss of hundreds of bitcoins and millions in losses. semanticscholar+1

Conclusion

Private key lifecycle management is a fundamental security element for Bitcoin and other cryptocurrencies. The Vanguard Keystore attack, which implements a private key compromise attack, threatens the entire Bitcoin architecture. The following are required:

strict implementation of protection during storage and cleaning of keys;
isolation of important data in special secure containers;
Regular audits and automated code review. globalsign+1

Major cryptographic vulnerability

In the presented code, private keys are never deleted from memory after generation, but are stored forever in the container keystore. This allows any code with access to keystoreto retrieve all generated private keys.

The specific vulnerable line (inside the key generation loop):

cpp:

keystore.keys.emplace(key_id, privkey);

This is where each generated signature privkeyis placed in keystore.keysand remains in memory after the signature is complete.

To eliminate this leak , you need to delete the key from keystoreimmediately after use or use temporary storage that is cleared automatically.

BitCoreFinder: Forensic Cryptographic Forensics Tool for Detecting and Mitigating Keystore Vanguard Attack in Bitcoin Core Key Lifecycle Vulnerabilities

This paper presents a detailed examination of BitCoreFinder, a specialized forensic and diagnostic instrument designed to identify and mitigate vulnerabilities caused by improper key lifecycle management in Bitcoin Core, specifically focusing on the Keystore Vanguard Attack. Through memory forensics, entropy mapping, and key container verification, BitCoreFinder provides a systematic method to detect compromised cryptographic materials within live processes or memory dumps. This research explores the operational principles of BitCoreFinder and its application in reconstructing or protecting Bitcoin wallets affected by private key exposure due to CVE‑2023‑37192 and CVE‑2025‑27840.

1. Introduction: Private Key Lifecycle Threats

In the Bitcoin ecosystem, the confidentiality and integrity of private keys are paramount. Any weakness in the key lifecycle—generation, usage, or destruction—creates an opportunity for total compromise. The Keystore Vanguard Attack revealed a critical design flaw: keys persistent in memory after benchmarking remain unencrypted, vulnerable to extraction from RAM or dump files.
This issue emphasizes the need for an analytical mechanism capable of scanning internal memory layouts and identifying nonzero-entropy clusters that match ECDSA key structures from the secp256k1 curve. BitCoreFinder was developed to serve this exact forensic and diagnostic function.

2. Overview of BitCoreFinder Framework

BitCoreFinder operates at the intersection of cryptanalytic verification and low‑level forensic probing. Its architecture includes three principal modules:

Memory Analyzer Core (MAC): Scans address spaces to identify nonvolatile sequences matching elliptic curve key length and entropy profiles.
Signature Reconstruction Engine (SRE): Attempts to validate recovered key candidates by reconstructing ECDSA signatures against blockchain transaction datasets.
Forensic Consistency Layer (FCL): Annotates key findings with process origin, timestamp, and keystore mapping, enabling forensic reconstruction of compromised wallet states.

BitCoreFinder thus acts as a crypto‑forensic radar for detecting residual private key material that should have been cleared after cryptographic operations.

3. Methodology: Detecting the Keystore Vanguard Infection

During a Keystore Vanguard exploitation event, unemptied containers within keystore.keys accumulate raw private key material. BitCoreFinder detects these conditions using:

Entropy Mapping: Locates 256‑bit high‑entropy blobs corresponding to private keys generated via secp256k1.
Memory Validation: Confirms whether each blob matches ECDSA key criteria (valid scalar < n, where n is the curve order).
Contextual Correlation: Correlates memory addresses against process debug symbols (if accessible) to identify proximity to keystore structures.
Leakage Certification: Classifies findings as Active Residuals (live process leakage) or Dormant Residuals (dump artifacts).

This methodology allows analysts to identify systemic flaws before large‑scale Bitcoin theft occurs.

4. Exploitation Vector and Critical Impact

When an attacker exploits CVE‑2023‑37192 or CVE‑2025‑27840, they can read from volatile memory segments during or after benchmark operations. Once private keys are extracted, an attacker gains full wallet control and can authorize any transaction.
BitCoreFinder demonstrates that this vulnerability effectively transforms Bitcoin Core into a self‑exposing wallet service when running uncontrolled benchmark routines. A forensic scan performed by BitCoreFinder post‑incident typically reveals a complete map of ECDSA key material offsets, enabling reconstruction of compromised wallets.

The broader implication extends beyond Bitcoin Core: any cryptographic system that fails to sanitize memory after use faces a similar existential risk.

5. Scientific Framework for Vulnerability Analysis

BitCoreFinder’s research foundation follows key principles of modern cryptographic forensics:

Differential Entropy Profiling: Recognizing specific entropy signatures of cryptographic secrets.
Volatile Memory Trace Acquisition: Low‑level extraction using DMA or kernel capture frameworks.
Key Lifecycle Verification: Ensuring memory clearing mechanisms (memset_s, RAII destructors) are applied consistently.
Anomaly Correlation to CVE Chains: Mapping findings to standardized identifiers such as CVE‑2023‑37192 (software memory leak vector) and CVE‑2025‑27840 (hardware IoT key exposure).

This alignment with formal vulnerability classification allows BitCoreFinder reports to serve in responsible disclosure processes and software remediation audits.

6. Role in Bitcoin Wallet Recovery

In cases where wallets are lost because of memory‑retained private keys, BitCoreFinder’s controlled forensic recovery provides legitimate remediation. It can scan authenticated memory images from user systems, identify mismanaged key artifacts, and reconstruct original private keys for lawful wallet restoration.
This dual functionality—both as a defensive detector and a forensic recovery facilitator—positions BitCoreFinder as a crucial instrument in cryptocurrency security analysis.

7. Mitigation Strategy and Integration

To neutralize the Keystore Vanguard vulnerability, BitCoreFinder integrates with secure development pipelines:

It automatically verifies that cryptographic objects are zeroized post‑usage.
It generates audit reports on key presence persistence time.
It supports alerting for non‑cleared keystore structures in runtime.

Furthermore, its modular plugin allows integration with CI systems (e.g., Jenkins, GitHub Actions) to ensure security regression compliance within the Bitcoin Core codebase.

8. Conclusion: Scientific and Strategic Significance

The emergence of the Keystore Vanguard Attack marks a new phase of cryptographic warfare targeting lifecycle management flaws rather than algorithmic weaknesses. BitCoreFinder acts as both a microscope and a shield for Bitcoin security research, illuminating memory residues invisible to standard debugging methods.
Through systematic entropy mapping, forensic validation, and secure cleanup monitoring, BitCoreFinder not only uncovers the full extent of the private key compromise but also establishes a new paradigm for preventive cryptographic memory hygiene.
Its widespread implementation would dramatically reduce the risks of silent key compromise and protect the structural integrity of Bitcoin’s decentralized trust model.

A critical cryptographic vulnerability related to private key management in Bitcoin Core was identified as part of a scientific study. This paper explains the nature of the issue, the mechanism by which it occurs, and presents a reasonable, secure solution with explanations and sample code.

Introduction

Secure private key management is the foundation of Bitcoin’s cryptographic security. Keys, which hold absolute control over assets, require careful handling at all stages of their lifecycle. Violating these principles risks leaks and compromise of user funds. lightspark+1

The mechanism of vulnerability occurrence

In the original Bitcoin Core test or benchmark code, keys are generated in bulk and stored in a structure keystorewhere they are stored until the process is complete. Code:

cppkeystore.keys.emplace(key_id, privkey);

Places all private keys in a container that is not cleaned up after use. Thus, an attacker with access to the process’s memory can extract all accumulated private keys, resulting in asset compromise. utimaco+1

Main mistakes:

Loss of Key Lifecycle Management: Private keys are stored unnecessarily and for excessively long periods of time. geeksforgeeks
No container cleanup: After signing operations are completed, keys are not removed from memory.
Vulnerability to memory dumps and malware attacks: Any analysis of process memory risks completely compromising all accumulated private keys.

Safe fix and protection

Best practices for protection:

Limit the lifetime of cryptographic material. Private keys should be stored in memory only for the time needed to perform a specific operation (e.g., signing). globalsign+1
Delete the key immediately after the operation is complete. Use a temporary container for storage and perform explicit erasing.
Avoid storing references to keys in global and static structures.

Example of a safe fix:

A secure approach is to store the private key only for the duration of the signing and immediately clear the container after completion:

cpp// Безопасный вариант: генерация, использование и безопасное удаление
std::vector<CKey> temp_keys;
for (int i = 0; i < 32; i++) {
    CKey privkey = GenerateRandomKey();
    // Используем ключ только для создания подписи:
    UsePrivateKey(privkey); // функция, использующая ключ для подписания

    // После использования сразу затираем память:
    privkey.Clear();

    // Храним только на время необходимое для подписи
    temp_keys.push_back(privkey);
}

// По завершении операции полностью очищаем буфер:
for (auto& key : temp_keys) key.Clear();
temp_keys.clear();

Alternative: Use scoped containers or special types that support automatic RAII memory erasure.

Correction form for keystore:

Modify the code so that keys are added to the store only during signing, and after the operation is completed, the keys are deleted:

cppkeystore.keys.emplace(key_id, privkey);
// ... операция подписи ...
keystore.keys.erase(key_id); // удаление ключа после использования

It is also worth implementing memory clearing by calling a method that ensures the erasure of the contents of the private key.

Conclusion

Proper management of cryptographic key lifetimes is a fundamental security measure in Bitcoin Core. The proposed fix eliminates the accumulation of sensitive data in process memory and significantly reduces the risk of attacks—both local (memory dumps) and malware. By implementing these methods, the developers ensure the protection of crypto assets and the trust of Bitcoin network users. utimaco+1

Final scientific conclusion

Understanding and promptly addressing such vulnerabilities is crucial to the survival and development of Bitcoin as the world’s leading cryptocurrency by market capitalization and the benchmark for digital autonomy in the new millennium. papers.ssrn+2

Bibliography

Key Leakage of Bitcoin Users, Christian Rossow, M. Brengel. The International Symposium on Research in Attacks, Intrusions and Defenses (RAID), 2018. publications.cispa+1
CVE-2023-37192. NIST Database. cvedetails+2
Critical Vulnerabilities of Private Keys in BitcoinLib, 2025. keyhunters
Key Management Lifecycle Best Practices, CSA. cloudsecurity alliance
Zimperium, Top 5 Cryptographic Key Protection Best Practices, 2025. zimperium