CVE-2018-18206 in Bytom
Summary
by MITRE
In the client in Bytom before 1.0.6, checkTopicRegister in p2p/discover/net.go does not prevent negative idx values, leading to a crash.
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Analysis
by VulDB Data Team • 05/23/2023
The vulnerability identified as CVE-2018-18206 resides within the Bytom cryptocurrency client software version 1.0.5 and earlier, specifically within the peer-to-peer discovery mechanism. This flaw manifests in the checkTopicRegister function located in the p2p/discover/net.go file, where inadequate input validation permits negative index values to propagate through the system. The issue represents a classic buffer underflow condition that occurs when the system attempts to process topic registration requests with invalid index parameters. The absence of proper bounds checking in this critical network communication component creates a scenario where malicious actors can exploit the lack of input sanitization to disrupt normal client operations.
The technical implementation of this vulnerability stems from a failure in the network discovery protocol's topic registration handling logic. When the checkTopicRegister function processes incoming topic registration messages, it fails to validate that the index parameter remains within acceptable positive integer bounds. This oversight allows negative index values to be accepted and subsequently processed by the system's internal data structures. The consequence of this flaw is a direct crash condition that terminates the client application's execution, effectively causing a denial of service for legitimate network participants. The vulnerability operates at the network protocol level, specifically targeting the peer-to-peer communication infrastructure that enables nodes to discover and connect with each other within the Bytom blockchain network.
From an operational impact perspective, this vulnerability compromises the stability and reliability of the Bytom client software, potentially affecting the overall health of the blockchain network. The crash condition can be triggered through malformed network messages sent to vulnerable clients, making it exploitable by attackers who can remotely disrupt service without requiring authentication or elevated privileges. This represents a significant concern for network participants who depend on continuous client operation for transaction processing, mining activities, or network maintenance. The vulnerability also exposes potential risks for network decentralization, as coordinated exploitation could lead to widespread client failures and network fragmentation. The impact extends beyond individual client crashes to potentially affect the broader blockchain ecosystem's operational integrity and user confidence in the platform's reliability.
The vulnerability aligns with CWE-129, which addresses improper validation of array index values, and demonstrates characteristics consistent with ATT&CK technique T1499.002, which involves network disruption through service availability attacks. Mitigation strategies should focus on implementing robust input validation mechanisms within the checkTopicRegister function to ensure all index values fall within expected parameter ranges. The recommended fix involves adding explicit bounds checking before any array or slice operations, ensuring that negative indices are rejected and appropriate error handling is implemented. Additionally, the system should enforce proper integer type validation and implement defensive programming practices to prevent similar issues in related network components. Network administrators should prioritize updating to Bytom version 1.0.6 or later, which includes the necessary patches to address this vulnerability and restore normal client functionality. The fix should also include enhanced logging capabilities to detect and alert on anomalous network traffic patterns that might indicate attempted exploitation of similar vulnerabilities.