CVE-2018-13717 in HormitechToken
Summary
by MITRE
The mintToken function of a smart contract implementation for HormitechToken, 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 • 02/28/2020
The vulnerability identified as CVE-2018-13717 represents a critical integer overflow flaw within the mintToken function of the HormitechToken smart contract deployed on the Ethereum blockchain. This vulnerability stems from inadequate input validation and arithmetic overflow handling within the contract's code implementation, creating a scenario where the contract owner can manipulate user balances arbitrarily. The flaw exists at the core level of the token's functionality, specifically in how the contract processes token minting operations and updates user account balances. When the mintToken function executes, it fails to properly validate or constrain the parameters passed to it, allowing malicious or accidental manipulation of balance calculations through integer overflow conditions.
The technical exploitation of this vulnerability occurs when an attacker or contract owner invokes the mintToken function with carefully crafted parameters that trigger integer overflow behavior. This condition arises from the use of unsigned integer types without proper overflow checks, a common pattern in Solidity smart contracts that can lead to unexpected behavior when arithmetic operations exceed maximum representable values. The vulnerability directly maps to CWE-190, which describes integer overflow and underflow conditions, and represents a significant security weakness in the contract's access control and state management mechanisms. When the overflow occurs, the contract's balance calculation wraps around to an unexpected value, allowing the owner to effectively set any user's balance to an arbitrary value, potentially leading to unlimited token issuance or manipulation of user holdings.
The operational impact of this vulnerability extends beyond simple balance manipulation, as it fundamentally compromises the integrity and trustworthiness of the HormitechToken ecosystem. An attacker with access to the contract owner account can arbitrarily inflate user balances, potentially leading to massive economic disruption within the token's ecosystem. The vulnerability also creates opportunities for denial of service attacks where malicious actors could manipulate balances to zero, effectively freezing user accounts or making tokens unusable. From an attacker perspective, this flaw aligns with ATT&CK technique T1059.001 for command and control through smart contract manipulation and T1496 for resource hijacking by exploiting contract owner privileges. The vulnerability undermines the fundamental principles of blockchain tokenomics and can lead to complete loss of user funds or token value destruction.
Mitigation strategies for CVE-2018-13717 require immediate code remediation through comprehensive input validation and overflow protection mechanisms. The smart contract implementation must incorporate proper bounds checking and use safe arithmetic operations such as those provided by OpenZeppelin's SafeMath library to prevent integer overflow conditions. Contract owners should implement robust access control measures and consider using multi-signature wallets for critical operations to reduce the risk of unauthorized exploitation. Additionally, thorough code auditing and formal verification processes should be conducted to identify similar vulnerabilities across the entire smart contract ecosystem. The fix should include explicit validation of mintToken function parameters, implementation of overflow protection mechanisms, and comprehensive testing of edge cases including maximum value scenarios. Regular security assessments and continuous monitoring of contract behavior are essential to prevent similar vulnerabilities from emerging in future contract versions or related smart contract implementations.