CVE-2018-13598 in SendMe
Summary
by MITRE
The mintToken function of a smart contract implementation for SendMe, 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 in CVE-2018-13598 represents a critical integer overflow flaw within the mintToken function of the SendMe Ethereum token smart contract implementation. This vulnerability resides in the core token management logic where the contract owner possesses elevated privileges to manipulate user balances through improper input validation. The flaw manifests when the mintToken function processes token minting operations without adequate overflow checks, creating a scenario where arithmetic operations can exceed the maximum value representable by the underlying data type.
The technical nature of this vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions in software implementations. In Ethereum smart contracts, this typically occurs when unsigned integer operations exceed their maximum capacity, causing the value to wrap around to zero or negative values. The mintToken function in question likely performs arithmetic operations on token balances or supply calculations without proper bounds checking, allowing an attacker with owner privileges to manipulate the mathematical operations in ways that produce unexpected results. This creates a path where the owner can specify arbitrary balance values for any user account within the token system.
The operational impact of this vulnerability extends beyond simple balance manipulation, as it fundamentally compromises the integrity and security of the entire token ecosystem. An attacker with owner access can essentially create unlimited tokens for themselves or other users, potentially leading to massive dilution of token value and complete control over the token distribution. The vulnerability enables a range of malicious activities including unauthorized token creation, balance manipulation for fraudulent purposes, and potential exploitation of other contract functions that depend on accurate token balances. This represents a severe compromise of the trust model that Ethereum tokens rely upon, as users cannot guarantee the accuracy of their balances or the scarcity of the token supply.
Mitigation strategies for this vulnerability require immediate implementation of comprehensive input validation and overflow protection mechanisms within the smart contract code. The mintToken function must incorporate proper bounds checking using safe arithmetic libraries or explicit overflow detection before performing any mathematical operations. The contract should validate all input parameters including recipient addresses and token amounts to prevent malicious manipulation. Additionally, implementing access control measures that limit the scope of owner privileges and adding transaction logging for all mint operations can help detect and prevent unauthorized activities. The vulnerability also highlights the importance of formal verification processes and comprehensive testing including edge case scenarios to identify similar issues before deployment. Organizations should consider adopting security frameworks such as those recommended by the OpenZeppelin security guidelines and implementing continuous monitoring of smart contract operations to detect anomalous behavior patterns that may indicate exploitation attempts.