CVE-2018-13599 in ResidualValue
Summary
by MITRE
The mintToken function of a smart contract implementation for ResidualValue, 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-2018-13599 represents a critical integer overflow flaw within the mintToken function of a smart contract implementation for ResidualValue, an Ethereum-based token. This vulnerability resides in the core token functionality that governs the creation and distribution of new tokens within the contract ecosystem. The flaw manifests when the mintToken function processes token minting operations without proper overflow checks, creating a scenario where arithmetic operations can exceed the maximum value that can be represented by the underlying data type. This specific implementation issue affects the balance management system of the token contract, allowing unauthorized manipulation of user account balances through controlled overflow conditions.
The technical execution of this vulnerability leverages the fundamental properties of integer arithmetic within smart contract environments. When the mintToken function attempts to increment token balances, it fails to validate whether the resulting value would exceed the maximum limit of the integer data type being used. This oversight creates a predictable overflow condition where the arithmetic operation wraps around to a much smaller value, effectively allowing an attacker to manipulate account balances by carefully crafting the minting parameters. The vulnerability is particularly dangerous because it grants the contract owner the ability to set arbitrary user balances to any desired value, bypassing normal tokenomics and potentially enabling fraudulent token distribution or account manipulation.
The operational impact of this vulnerability extends beyond simple balance manipulation to encompass broader security implications for the entire token ecosystem. An attacker with access to the owner privileges could artificially inflate or deflate user balances, potentially creating scenarios where users might receive excessive token allocations or lose their entire holdings through controlled overflow conditions. This vulnerability undermines the fundamental trust model of blockchain-based token systems, as it allows for the arbitrary modification of token distributions without proper authorization or transparent accounting. The implications are particularly severe for financial applications where token balances represent actual assets, as this flaw could lead to significant financial losses for users and potential regulatory violations for the token issuer.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements to prevent similar issues in future implementations. The primary fix involves implementing proper overflow checks using safe arithmetic libraries or explicit validation before any arithmetic operations that could potentially exceed data type limits. This approach aligns with CWE-191, which specifically addresses integer underflow and overflow conditions in software implementations. Additionally, contract owners should implement comprehensive access controls and audit mechanisms to detect unauthorized balance manipulations. The implementation of automated testing protocols and formal verification methods can help identify such vulnerabilities during development phases, reducing the risk of similar issues in production environments. Organizations should also consider implementing multi-signature wallets and time-locked transactions for critical operations to add additional layers of security and accountability to token management functions.