CVE-2018-13508 in VITToken
Summary
by MITRE
The mintToken function of a smart contract implementation for VITToken, 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-2018-13508 represents a critical integer overflow flaw within the mintToken function of the VITToken smart contract implementation on the Ethereum blockchain. This vulnerability stems from inadequate input validation and arithmetic operation handling within the contract's codebase, creating a scenario where the contract owner can manipulate user balances arbitrarily. The flaw occurs when the mintToken function processes token minting operations without proper overflow checks, allowing malicious actors with contract ownership privileges to execute calculations that exceed the maximum value representable by the underlying data type.
The technical implementation of this vulnerability falls under CWE-190, which specifically addresses integer overflow and underflow conditions in software systems. In the context of smart contracts, this vulnerability represents a severe privilege escalation issue where the contract owner can manipulate the state of the blockchain by directly modifying user balance values. The integer overflow occurs during the arithmetic operations performed within the mintToken function, where the addition of new tokens to a user's balance can exceed the maximum value permitted by the data type, causing the value to wrap around to an unintended lower value. This wrapping behavior enables the contract owner to set any user's balance to an arbitrary value, effectively allowing for unauthorized token manipulation and potential theft of funds.
The operational impact of this vulnerability extends beyond simple balance manipulation to encompass broader security implications for the entire token ecosystem. Attackers with access to the contract owner account can exploit this flaw to inflate their own token holdings or reduce other users' balances to zero, creating a scenario where the integrity of the token distribution is completely compromised. The vulnerability also enables potential denial-of-service attacks where malicious actors can manipulate token balances to prevent legitimate users from accessing their funds. From a blockchain security perspective, this issue demonstrates the critical importance of proper input validation and arithmetic operation safety in smart contract development, as the immutable nature of blockchain transactions means that such vulnerabilities cannot be easily corrected once deployed.
Mitigation strategies for this vulnerability require immediate attention through contract code review and potential redeployment of a patched version. The recommended approach involves implementing comprehensive overflow and underflow checks using modern Solidity practices, including the use of SafeMath libraries or compiler versions that enforce overflow protection. Additionally, the contract owner should implement proper access controls and consider using multi-signature wallets to distribute ownership privileges and reduce the risk of unauthorized access. The vulnerability also highlights the necessity of thorough security auditing and formal verification processes for smart contracts before deployment, as outlined in industry best practices for blockchain security. Organizations should also implement monitoring systems to detect unusual balance changes that might indicate exploitation of similar vulnerabilities, ensuring that the security posture of their blockchain assets remains robust against evolving threats.