CVE-2018-13469 in IcoContract
Summary
by MITRE
The mintToken function of a smart contract implementation for IcoContract, 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 • 02/26/2020
The vulnerability identified as CVE-2018-13469 represents a critical integer overflow flaw within the mintToken function of an Ethereum-based smart contract implementation for IcoContract tokens. This vulnerability resides in the core token management functionality of the smart contract, specifically affecting how token balances are incremented and managed. The flaw allows the contract owner to manipulate token balances in ways that violate the fundamental principles of blockchain tokenomics and financial integrity. The integer overflow occurs when the mintToken function attempts to increment a user's balance without proper bounds checking, creating a scenario where arithmetic operations can wrap around to unexpected values. This vulnerability directly impacts the security model of the token contract and undermines trust in the token's distribution mechanism.
The technical implementation of this vulnerability stems from improper input validation within the mintToken function, which fails to verify that balance increments remain within acceptable numerical bounds. When an attacker or contract owner invokes this function with carefully crafted parameters, the integer overflow allows for arbitrary balance manipulation that can result in either overflow or underflow conditions. The vulnerability maps directly to CWE-190, which describes integer overflow and underflow conditions in software implementations. This flaw enables the contract owner to bypass normal token minting restrictions and potentially create unlimited token supply, leading to severe economic consequences for token holders and the overall ecosystem. The issue is particularly dangerous because it operates at the contract level rather than requiring external interactions, making it exploitable directly by the contract owner without additional attack vectors.
The operational impact of CVE-2018-13469 extends far beyond simple balance manipulation, creating cascading effects throughout the token economy and potentially compromising the entire smart contract system. An attacker with owner privileges can inflate token balances of specific users, manipulate token distributions, or even create artificial scarcity by reducing other users' balances. This vulnerability directly violates the principles of decentralized finance and blockchain transparency, as it allows for hidden manipulation of token holdings. The consequences include potential loss of funds for legitimate token holders, disruption of token trading markets, and erosion of confidence in the entire token ecosystem. Additionally, this vulnerability can be leveraged to execute other attacks such as front-running, manipulation of token prices, or exploitation of token-based governance systems. The impact is further amplified by the fact that such vulnerabilities often remain undetected for extended periods, allowing for prolonged exploitation and damage to token value.
Mitigation strategies for CVE-2018-13469 must address both immediate remediation and long-term security architecture improvements. The primary fix involves implementing comprehensive input validation and boundary checking within the mintToken function to prevent integer overflow conditions. This includes utilizing safe arithmetic operations and employing libraries such as OpenZeppelin's SafeMath to handle mathematical operations securely. The contract should also implement proper access controls and audit trails to monitor balance modifications, ensuring that any unauthorized balance changes are detectable. Security best practices dictate that all arithmetic operations within smart contracts should be validated against potential overflow conditions, with explicit checks for maximum value limits. Organizations should also implement comprehensive code review processes that specifically target integer overflow vulnerabilities and establish continuous monitoring systems for detecting anomalous balance changes. The remediation process must include thorough testing of all token management functions, including edge cases and boundary conditions, to ensure that similar vulnerabilities do not exist in other contract functions. Additionally, implementing formal verification methods and security audits can help identify and prevent similar issues in future smart contract deployments, aligning with industry standards such as those outlined in the NIST Cybersecurity Framework and ISO/IEC 27001 security requirements.