CVE-2018-13530 in HunterCoin
Summary
by MITRE
The mintToken function of a smart contract implementation for HunterCoin, an Ethereum token, has an integer overflow that allows the owner of the contract to set the balance of an arbitrary user to any value.
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Analysis
by VulDB Data Team • 02/27/2020
The vulnerability identified in CVE-2018-13530 represents a critical integer overflow flaw within the mintToken function of HunterCoin smart contract implementation on the Ethereum blockchain. This vulnerability stems from inadequate input validation and arithmetic overflow handling within the token contract's codebase, creating a scenario where the contract owner can manipulate user balances arbitrarily. The flaw exists in the core token distribution mechanism, allowing malicious actors with contract ownership privileges to exploit the vulnerability without requiring external interactions or additional privileges beyond their existing administrative access.
The technical implementation of this vulnerability manifests through improper handling of integer arithmetic operations within the mintToken function. When the contract attempts to increment user balances or perform token minting operations, the system fails to validate whether the resulting values would exceed the maximum limits of the integer data types being used. This creates an overflow condition where arithmetic operations wrap around to unexpected values, enabling the contract owner to manipulate balance calculations in ways that bypass normal tokenomics constraints. The vulnerability operates at the fundamental level of the contract's mathematical operations, making it particularly dangerous as it affects the core accounting mechanisms of the token system.
The operational impact of this vulnerability extends far beyond simple balance manipulation, as it fundamentally compromises the integrity and trustworthiness of the token ecosystem. An attacker with ownership privileges can inflate or deflate user balances to arbitrary values, potentially enabling them to create unlimited tokens, manipulate market prices, or execute unauthorized transfers. This vulnerability undermines the decentralized trust model that blockchain tokens are designed to provide, as it allows the contract owner to override normal token economics and user expectations. The implications are severe for token holders who may lose confidence in the system's ability to maintain accurate balances and fair distribution mechanisms.
From a cybersecurity perspective, this vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions in software implementations. The flaw also maps to several ATT&CK techniques including T1059.001 for command and scripting interpreter execution and T1548.001 for abuse of privileges, as the contract owner leverages their administrative capabilities to exploit the underlying code vulnerability. Additionally, the vulnerability demonstrates characteristics of T1499.001 for network denial of service and T1566.001 for spearphishing with social engineering, as the compromised contract could be used to manipulate token distributions and potentially affect broader network participants.
Mitigation strategies for this vulnerability require immediate contract code remediation through comprehensive input validation and overflow protection mechanisms. The smart contract implementation must incorporate explicit bounds checking and use secure arithmetic operations that prevent integer overflow conditions. Additionally, the contract owner should implement proper access controls and consider using established secure token contract frameworks that have undergone security audits. Regular security assessments and formal verification of smart contract code should become standard practice to identify and remediate similar vulnerabilities before they can be exploited in production environments. The implementation of time locks, multi-signature requirements, and community governance mechanisms can further reduce the risk associated with contract ownership privileges and provide additional layers of security for token ecosystems.