CVE-2018-13577 in ShitCoin
Summary
by MITRE
The mintToken function of a smart contract implementation for ShitCoin (SHITC) (Contract Name: AdvancedShit), 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-2018-13577 represents a critical integer overflow flaw within the mintToken function of the AdvancedShit smart contract implementation for the ShitCoin token on the Ethereum blockchain. This vulnerability stems from inadequate input validation and arithmetic overflow handling within the contract's code, specifically affecting the token's minting mechanism that allows contract owners to create new tokens. The flaw manifests when the mintToken function processes token minting operations without proper bounds checking, enabling malicious actors with owner privileges to manipulate token balances through integer arithmetic overflow conditions.
The technical exploitation of this vulnerability occurs through the manipulation of integer variables within the mintToken function where the contract fails to validate that the resulting token balance will not exceed the maximum value representable by the integer data type. When the mintToken function executes with manipulated input parameters, it can cause the token balance to wrap around to an unintended value due to the overflow condition, effectively allowing the contract owner to set any user's token balance to an arbitrary value. This vulnerability directly maps to CWE-191 Integer Underflow/Overflow, which specifically addresses the improper handling of arithmetic operations that result in integer overflow or underflow conditions.
The operational impact of this vulnerability extends beyond simple balance manipulation, as it provides the contract owner with unprecedented control over the token distribution and potentially enables various malicious activities including unauthorized token creation, balance manipulation for financial gain, and potential disruption of token economics. The vulnerability affects the fundamental integrity of the token system by allowing the owner to bypass normal token minting restrictions and directly control user balances. This creates a significant risk for token holders and investors who rely on the contract's integrity for their token holdings and the overall security of their investments.
Mitigation strategies for this vulnerability require immediate implementation of comprehensive input validation and integer overflow protection mechanisms within the smart contract code. The recommended approach involves adding explicit bounds checking before any arithmetic operations within the mintToken function, implementing safe math libraries that prevent overflow conditions, and conducting thorough code audits to identify similar vulnerabilities throughout the contract implementation. Organizations should also consider implementing multi-signature ownership controls and regular security assessments to prevent unauthorized access to contract owner privileges. This vulnerability demonstrates the critical importance of secure smart contract development practices and adherence to established security frameworks such as those recommended by the OpenZeppelin security guidelines and the Ethereum Smart Contract Best Practices recommendations. The incident highlights the necessity of thorough testing and validation of all arithmetic operations in blockchain smart contracts to prevent similar vulnerabilities that could compromise the entire token ecosystem and user funds.