CVE-2018-13170 in Snoqualmie Coin
Summary
by MITRE
The mintToken function of a smart contract implementation for Snoqualmie Coin (SNOW), 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 • 02/25/2020
The vulnerability identified in CVE-2018-13170 represents a critical integer overflow flaw within the mintToken function of the Snoqualmie Coin (SNOW) smart contract deployed on the Ethereum blockchain. This vulnerability stems from inadequate input validation and arithmetic overflow handling within the contract's token minting mechanism, creating a scenario where the contract owner can manipulate user balances arbitrarily. The flaw directly impacts the fundamental security model of the token system by allowing unauthorized balance manipulation that bypasses normal transactional controls and consensus mechanisms inherent to blockchain technology.
The technical implementation of this vulnerability occurs when the mintToken function processes token minting operations without proper bounds checking on integer values. In Ethereum smart contracts, integer overflows occur when arithmetic operations exceed the maximum value that can be represented by the data type, causing the value to wrap around to zero or negative numbers. This specific implementation fails to validate the parameters passed to the mintToken function, allowing an attacker with contract ownership privileges to specify arbitrary balance values for target users. The vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions in software implementations.
From an operational perspective, this vulnerability creates severe financial and security implications for the SNOW token ecosystem. The contract owner can effectively create unlimited tokens for themselves while simultaneously manipulating other users' balances, potentially leading to massive wealth redistribution or complete loss of user funds. The impact extends beyond simple balance manipulation as it undermines the trust model of the token system and can be exploited to create artificial market conditions or execute sophisticated financial attacks. This vulnerability directly enables the attacker to bypass the normal tokenomics and governance mechanisms that should protect user holdings.
The exploitation of this vulnerability requires the attacker to possess the contract owner privileges, making it particularly dangerous as it represents an insider threat scenario within the token system. The attack vector is straightforward and can be executed through direct contract calls, making it difficult to detect in real-time operations. Security practitioners should note that this vulnerability demonstrates the critical importance of proper input validation and arithmetic boundary checking in smart contract development, as highlighted in the ATT&CK framework's smart contract security considerations. Organizations should implement comprehensive code review processes, formal verification techniques, and regular security audits to identify similar integer overflow vulnerabilities. The remediation approach involves implementing proper bounds checking, using safe arithmetic libraries, and ensuring that all user inputs are validated before processing. Additionally, the vulnerability underscores the necessity of implementing robust access control mechanisms and regular privilege audits to prevent unauthorized manipulation of critical contract functions, particularly those involving asset minting and balance modification operations.