CVE-2010-5137 in bitcoind
Summary
by MITRE
wxBitcoin and bitcoind before 0.3.5 allow remote attackers to cause a denial of service (daemon crash) via a Bitcoin transaction containing an OP_LSHIFT script opcode.
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Analysis
by VulDB Data Team • 02/19/2019
The vulnerability identified as CVE-2010-5137 represents a critical denial of service flaw affecting early versions of Bitcoin daemon implementations including wxBitcoin and bitcoind prior to version 0.3.5. This weakness stems from insufficient input validation within the Bitcoin transaction processing pipeline, specifically when handling script opcodes that are part of the Bitcoin scripting language used to define transaction conditions and unlock funds.
The technical flaw manifests through the improper handling of the OP_LSHIFT script opcode which is designed to perform bitwise left shift operations within Bitcoin transaction scripts. When malicious actors submit Bitcoin transactions containing this opcode with malformed parameters or excessive shift values, the Bitcoin daemon processes these inputs without adequate bounds checking or error handling. This processing failure results in a daemon crash and subsequent denial of service condition that affects the entire Bitcoin network node running the vulnerable software version.
This vulnerability directly impacts the operational integrity of Bitcoin networks by enabling attackers to disrupt service availability through simple transaction submissions. The attack requires minimal resources and technical expertise, making it particularly dangerous as it can be executed by anyone with access to the Bitcoin network. The daemon crash effectively removes the affected node from network participation, potentially weakening the overall network consensus and transaction processing capabilities. From a cybersecurity perspective, this represents a classic buffer overflow or integer overflow condition where the system fails to properly validate numeric inputs before processing them.
The operational impact extends beyond immediate service disruption as it can be leveraged to create network partitioning effects or to target specific nodes for sustained denial of service attacks. Network participants relying on these vulnerable implementations face significant risks to their service availability and transaction processing capabilities. The vulnerability also highlights the importance of proper input validation and error handling in cryptocurrency implementations, where even seemingly benign script opcodes can be weaponized for network disruption.
Organizations and developers should implement immediate mitigations including upgrading to Bitcoin daemon versions 0.3.5 or later, which contain proper bounds checking for script opcodes. Additionally, network administrators should consider implementing transaction filtering mechanisms to detect and reject transactions containing potentially malicious script opcodes. The vulnerability aligns with CWE-129, which addresses improper validation of array indices, and represents a classic example of how script validation flaws can be exploited for denial of service attacks. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique for network denial of service, where adversaries leverage weaknesses in system implementations to disrupt network availability. The remediation approach should include comprehensive testing of script processing routines and implementation of robust input sanitization mechanisms to prevent similar vulnerabilities from emerging in future deployments.