CVE-2018-13757 in Coinquer
Summary
by MITRE
The mintToken function of a smart contract implementation for Coinquer, 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 • 03/03/2020
The vulnerability identified as CVE-2018-13757 represents a critical integer overflow flaw within the mintToken function of the Coinquer Ethereum token smart contract implementation. This vulnerability falls under the CWE-190 category of integer overflow and under the CWE-682 category of incorrect arithmetic operations. The flaw exists in the contract's logic where the mintToken function fails to properly validate or constrain integer values during balance updates, creating a scenario where the owner can manipulate token balances without proper authorization.
The technical exploitation of this vulnerability occurs through the mintToken function which allows the contract owner to mint new tokens and assign them to specific addresses. Due to the absence of proper overflow checks, an attacker with owner privileges can manipulate the balance calculation to set any user's token balance to an arbitrary value. This occurs because the smart contract does not implement proper bounds checking or validation mechanisms to prevent integer overflow conditions during arithmetic operations involving token balances.
The operational impact of this vulnerability is severe as it grants the contract owner unlimited control over token distribution and user balances. An attacker can potentially manipulate token supply, create unlimited tokens for themselves, or set other users' balances to zero or extremely high values. This vulnerability directly violates the fundamental principles of tokenomics and can lead to complete loss of user funds or manipulation of token economics. The vulnerability affects all users of the Coinquer token who rely on the integrity of their balances and the fair distribution of tokens within the ecosystem.
Mitigation strategies for this vulnerability require immediate implementation of proper integer overflow protection mechanisms within the smart contract code. Developers should implement explicit bounds checking and use safe arithmetic operations that prevent overflow conditions. The recommended approach includes using libraries such as OpenZeppelin's SafeMath or similar libraries that provide overflow protection for arithmetic operations. Additionally, comprehensive testing procedures including formal verification and security audits should be implemented to identify similar vulnerabilities in other smart contract functions. The vulnerability also highlights the importance of following secure coding practices for smart contracts and adhering to established security frameworks such as those outlined in the Ethereum Smart Contract Security Best Practices recommendations. Organizations should also consider implementing multi-signature ownership mechanisms and regular security assessments to prevent unauthorized access to contract owner privileges that could exploit such vulnerabilities.