CVE-2010-5140 in bitcoind
Summary
by MITRE
wxBitcoin and bitcoind before 0.3.13 do not properly handle bitcoins associated with Bitcoin transactions that have zero confirmations, which allows remote attackers to cause a denial of service (invalid-transaction flood) by sending low-valued transactions without transaction fees.
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Analysis
by VulDB Data Team • 02/19/2019
The vulnerability identified as CVE-2010-5140 affects wxBitcoin and bitcoind software versions prior to 0.3.13, representing a critical flaw in the Bitcoin protocol implementation that specifically targets the handling of zero-confirmation transactions. This issue stems from inadequate validation mechanisms within the transaction processing pipeline, where the software fails to properly manage transactions that lack any confirmation on the blockchain. The flaw creates a significant security gap that enables malicious actors to exploit the system through a well-crafted denial of service attack pattern. The vulnerability is particularly concerning because it operates at the core protocol level, affecting how the Bitcoin network validates and processes transactions, thereby undermining the fundamental integrity of the distributed ledger system.
The technical implementation of this vulnerability lies in the improper handling of transaction validation logic within the Bitcoin client software. When transactions with zero confirmations are received, the affected versions fail to implement adequate filtering mechanisms to distinguish between legitimate and malicious transactions. This deficiency allows attackers to flood the network with low-valued transactions that contain no transaction fees, creating an invalid transaction flood that overwhelms the system's processing capabilities. The flaw specifically manifests in the client's inability to properly validate transaction inputs and outputs, particularly when dealing with transactions that have zero confirmations, which should normally be rejected or handled with extreme caution. This improper transaction handling creates a cascading effect where the system becomes overwhelmed with invalid transaction data, consuming computational resources and network bandwidth.
The operational impact of CVE-2010-5140 extends beyond simple service disruption, creating a broader threat to the Bitcoin network's stability and security. Attackers can leverage this vulnerability to perform sustained denial of service attacks that effectively render Bitcoin nodes unusable, as the system becomes flooded with invalid transaction data that cannot be properly processed. The attack vector is particularly insidious because it exploits the legitimate functionality of the Bitcoin protocol while subverting its intended behavior, making detection and mitigation more challenging. The lack of transaction fees in these malicious transactions further compounds the problem, as it provides no economic incentive for network participants to reject these invalid transactions, creating a scenario where the network becomes saturated with worthless data. This vulnerability directly impacts the network's ability to maintain proper transaction ordering and validation, potentially leading to broader consensus issues within the Bitcoin ecosystem.
From a cybersecurity perspective, this vulnerability aligns with CWE-400, which addresses the improper handling of resources, and represents a classic example of resource exhaustion attack patterns. The flaw also maps to ATT&CK technique T1499.004, which covers network denial of service attacks, demonstrating how this vulnerability can be exploited to create sustained network disruption. The attack methodology follows a well-established pattern where attackers exploit protocol weaknesses to consume system resources, similar to other network-based DoS attacks that have been documented in various cybersecurity frameworks. Mitigation strategies must include implementing proper transaction filtering mechanisms, establishing transaction fee requirements, and deploying rate limiting controls to prevent excessive transaction processing. Network administrators should also consider implementing transaction validation rules that reject zero-confirmation transactions or implement additional checks to identify potentially malicious transaction patterns.
The remediation approach for CVE-2010-5140 requires immediate software updates to version 0.3.13 or later, which includes enhanced transaction validation logic and proper handling of zero-confirmation transactions. Additionally, implementing proper transaction filtering rules that reject transactions without sufficient fees and establishing network-level controls to limit transaction processing rates can provide additional defense in depth. Organizations should also consider implementing transaction monitoring systems that can detect anomalous transaction patterns and automatically isolate potentially malicious traffic. The vulnerability underscores the critical importance of proper input validation and resource management in distributed systems, particularly those handling financial transactions where the integrity of the system directly impacts the security and availability of funds. Regular security audits and protocol validation should be conducted to ensure that similar vulnerabilities are not introduced in future implementations, emphasizing the need for comprehensive security testing throughout the software development lifecycle.