CVE-2018-13594 in CardFactory
Summary
by MITRE
The mintToken function of a smart contract implementation for CardFactory, 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 as CVE-2018-13594 resides within the mintToken function of a smart contract implementation for the CardFactory Ethereum token. This flaw represents a critical integer overflow vulnerability that fundamentally compromises the contract's integrity and security model. The vulnerability stems from insufficient input validation and arithmetic overflow handling within the token minting mechanism, allowing malicious actors to manipulate token balances arbitrarily. The issue specifically affects the contract's ability to maintain accurate accounting of token holdings, creating a pathway for unauthorized balance manipulation that directly violates the fundamental principles of blockchain-based asset management.
The technical implementation of this vulnerability occurs when the mintToken function processes token creation requests without proper overflow checks on the balance calculations. This integer overflow condition typically arises from the use of Solidity's default arithmetic operations that do not automatically check for overflow conditions, particularly when dealing with uint256 data types. The vulnerability enables an attacker with owner privileges to manipulate the internal balance tracking mechanism by exploiting the mathematical properties of integer arithmetic, where operations exceeding maximum value limits wrap around to zero or negative values. This flaw maps directly to CWE-191 Integer Underflow/Overflow, which specifically addresses the improper handling of integer arithmetic operations that can lead to unexpected behavior and security breaches.
The operational impact of this vulnerability extends beyond simple balance manipulation to encompass potential financial losses and complete contract compromise. An attacker can exploit this vulnerability to inflate any user's token balance to arbitrary values, potentially leading to massive token inflation and devaluation of the entire token ecosystem. The vulnerability also enables the creation of infinite token supply, which undermines the economic model and value proposition of the CardFactory token. Furthermore, this flaw can be leveraged to manipulate governance mechanisms if the token serves as a voting or decision-making asset within the ecosystem. The vulnerability affects all users of the contract and can result in immediate financial losses for token holders, as well as long-term damage to the project's credibility and trust within the Ethereum blockchain community.
Mitigation strategies for CVE-2018-13594 require immediate implementation of robust input validation and overflow protection mechanisms within the smart contract code. The recommended approach involves utilizing SafeMath libraries or similar arithmetic libraries that provide overflow-checked operations, ensuring that all balance calculations include proper bounds checking before execution. Contract owners should implement comprehensive testing procedures including unit tests, integration tests, and formal verification to identify similar vulnerabilities before deployment. Additionally, the implementation of access control measures and multi-signature requirements for critical functions like mintToken can reduce the attack surface. The vulnerability also highlights the importance of following secure coding practices as outlined in the OWASP Secure Coding Practices and aligns with ATT&CK technique T1210 Exploitation of Remote Services, specifically targeting smart contract vulnerabilities. Regular security audits and continuous monitoring of contract behavior are essential to detect and prevent similar vulnerabilities in future implementations, ensuring the long-term security and integrity of Ethereum-based token systems.