CVE-2018-13626 in SemainToken
Summary
by MITRE
The mintToken function of a smart contract implementation for SemainToken, 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-2018-13626 represents a critical integer overflow flaw within the mintToken function of the SemainToken smart contract deployed on the Ethereum blockchain. This vulnerability stems from inadequate input validation and arithmetic operation handling within the contract's code, specifically affecting the token's minting mechanism that allows contract owners to create new tokens. The integer overflow occurs when the contract attempts to increment token balances without proper bounds checking, enabling malicious actors with owner privileges to manipulate token quantities beyond the intended limits. Such a flaw fundamentally compromises the integrity of the token economy by allowing arbitrary balance manipulation that can lead to infinite token creation or manipulation of user holdings.
The technical exploitation of this vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions in software systems. When the mintToken function processes token minting operations, it fails to validate whether the resulting balance would exceed the maximum value that can be represented by the underlying data type, typically a 256-bit unsigned integer in Ethereum smart contracts. This oversight creates a scenario where an attacker can craft specific input values that cause the arithmetic operation to wrap around, resulting in unexpected and potentially malicious balance states. The vulnerability operates at the core of the contract's state management system, directly impacting the token's total supply and individual user balances through the owner-controlled minting functionality.
The operational impact of this vulnerability extends beyond simple balance manipulation to encompass broader security implications for the entire token ecosystem. An attacker with owner privileges can effectively create unlimited tokens or set any user's balance to arbitrary values, potentially leading to complete control over the token distribution and economic model. This vulnerability undermines the fundamental principles of blockchain tokenomics by allowing unauthorized wealth creation or destruction of user holdings, which could result in significant financial losses for token holders. The attack surface is particularly concerning as it targets the contract owner's privileged position, meaning that any compromise of owner credentials or private keys could lead to immediate exploitation of this vulnerability. The consequences include potential market manipulation, loss of investor confidence, and complete devaluation of the token if exploited successfully.
Mitigation strategies for CVE-2018-13626 should focus on implementing comprehensive input validation and arithmetic boundary checks within the smart contract code. Developers must ensure that all arithmetic operations within the mintToken function include proper overflow and underflow protection mechanisms, typically achieved through the use of safe math libraries or explicit bounds checking before performing balance updates. The contract should validate that the resulting balance after minting operations remains within acceptable limits and implement proper access control measures to prevent unauthorized minting activities. Additionally, regular security auditing and formal verification of smart contract code should be conducted to identify similar vulnerabilities before deployment. Organizations should also consider implementing multi-signature ownership models to distribute control and reduce the risk of single points of failure, aligning with best practices recommended in the Ethereum Smart Contract Security Best Practices framework and addressing the attack patterns documented in the MITRE ATT&CK framework for blockchain-based systems.