CVE-2018-13560 in KelvinToken
Summary
by MITRE
The mintToken function of a smart contract implementation for KelvinToken, 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-2018-13560 represents a critical integer overflow flaw within the mintToken function of the KelvinToken smart contract implementation on the Ethereum blockchain. This vulnerability stems from inadequate input validation and arithmetic overflow handling within the contract's code, creating a scenario where the contract owner can manipulate user balances arbitrarily. The issue manifests when the mintToken function processes token minting operations without proper overflow checks, allowing malicious or unauthorized operations to occur. The vulnerability directly impacts the fundamental integrity of the token's accounting system and can lead to severe financial consequences for users and the broader ecosystem.
The technical exploitation of this vulnerability occurs through the manipulation of integer arithmetic within the smart contract's mintToken function. When the contract attempts to increment a user's balance through token minting, the lack of overflow protection enables an attacker to cause the balance to wrap around to an unintended value. This type of vulnerability is classified under CWE-190 as an integer overflow or wraparound error, which represents a common weakness in smart contract implementations due to the absence of proper bounds checking mechanisms. The contract owner can leverage this flaw to set any user's balance to any desired value, effectively allowing for unauthorized token distribution or manipulation of user accounts.
The operational impact of this vulnerability extends beyond simple balance manipulation to encompass potential financial loss, market manipulation, and trust degradation within the token ecosystem. An attacker with owner privileges can drain funds from other users by setting their balances to zero, inflate their own holdings, or create artificial scarcity by manipulating supply distribution. This vulnerability undermines the core principles of blockchain-based token systems, where transparency and immutability of balances are fundamental requirements. The consequences can be severe for token holders who lose confidence in the system's integrity and for the overall market stability of the KelvinToken. The vulnerability also represents a significant risk to the broader Ethereum ecosystem, as similar flaws in other contracts could lead to widespread financial losses across multiple token implementations.
Mitigation strategies for this vulnerability require immediate implementation of proper integer overflow protection mechanisms within the smart contract code. The most effective approach involves utilizing safe arithmetic libraries or implementing explicit overflow checks before any arithmetic operations within the mintToken function. Contract developers should employ established patterns such as the OpenZeppelin SafeMath library or similar solutions that provide built-in overflow protection for all mathematical operations. Additionally, comprehensive code review processes and formal verification techniques should be implemented to identify similar vulnerabilities across the entire smart contract codebase. The fix must ensure that all balance updates and token minting operations include proper validation to prevent overflow conditions, while maintaining the intended functionality of the contract's core features. Regular security audits and continuous monitoring of smart contract deployments are essential to prevent similar vulnerabilities from emerging in future implementations and to maintain the integrity of blockchain-based financial systems.