CVE-2018-13517 in C3 Token
Summary
by MITRE
The mintToken function of a smart contract implementation for C3 Token (C3), 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 CVE-2018-13517 vulnerability affects the C3 Token smart contract implementation on the Ethereum blockchain, representing a critical integer overflow flaw in the mintToken function that fundamentally compromises the token's integrity and security model. This vulnerability arises from improper input validation and arithmetic operations within the smart contract code, where the mintToken function fails to properly check for overflow conditions when processing token minting operations. The flaw allows the contract owner to manipulate user balances arbitrarily, creating a severe privilege escalation vulnerability that undermines the fundamental trust model of the token system.
The technical implementation of this vulnerability stems from the lack of proper overflow checking mechanisms in the smart contract's arithmetic operations. When the mintToken function processes token minting requests, it performs calculations that can exceed the maximum value representable by the data type used, causing the value to wrap around to zero or negative values. This behavior creates a scenario where the contract owner can exploit the overflow condition to manipulate account balances, effectively allowing them to create unlimited tokens or set any user's balance to arbitrary values including extremely large numbers or zero. The vulnerability directly maps to CWE-191 Integer Underflow/Overflow, which is classified as a critical weakness in software security.
The operational impact of this vulnerability extends far beyond simple balance manipulation, as it fundamentally compromises the token's economic model and trust assumptions. An attacker with owner privileges can create infinite tokens, manipulate market dynamics, or drain funds from other users' accounts, potentially leading to complete loss of value for token holders. The vulnerability also enables sophisticated attacks such as balance manipulation for voting power consolidation, creating artificial market conditions, or even enabling front-running attacks against other users. This weakness creates a persistent threat that remains active throughout the contract's lifecycle and can be exploited repeatedly, making it particularly dangerous for any token ecosystem relying on the integrity of user balances.
Mitigation strategies for CVE-2018-13517 require immediate remediation through proper smart contract development practices and code auditing. The primary fix involves implementing comprehensive overflow and underflow checks using modern solidity features such as require statements with appropriate conditions or utilizing safe math libraries that automatically handle overflow detection. Additionally, the contract owner should implement proper access controls and consider using multi-signature wallets for critical operations to reduce the attack surface. Organizations should also conduct thorough security audits using tools like MythX, Slither, or Oyente to identify similar vulnerabilities in their smart contract implementations. This vulnerability aligns with ATT&CK technique T1548.001 for privilege escalation and T1499.004 for data manipulation, emphasizing the need for comprehensive security measures that address both immediate exploitation vectors and long-term defensive strategies in blockchain environments.