CVE-2018-13481 in TRIUM
Summary
by MITRE
The mintToken function of a smart contract implementation for TRIUM, 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-2018-13481 represents a critical integer overflow flaw within the mintToken function of the TRIUM Ethereum token smart contract implementation. This vulnerability resides in the core token functionality that allows for the creation of new tokens through the minting process, making it a fundamental security weakness that directly impacts the contract's integrity and the trustworthiness of the token ecosystem. The flaw specifically manifests in the contract's inability to properly validate or constrain integer values during the token minting operation, creating a scenario where the owner can manipulate balances beyond normal operational parameters.
The technical nature of this vulnerability aligns with CWE-190, which categorizes integer overflow conditions that can lead to unexpected behavior in software systems. In the context of Ethereum smart contracts, this overflow occurs when the mintToken function attempts to increment a user's balance without proper bounds checking or overflow protection mechanisms. The contract's implementation fails to validate that the resulting balance value remains within acceptable integer limits, allowing an attacker with owner privileges to exploit this weakness by providing malicious input values that cause the integer arithmetic to wrap around to unintended values. This creates a scenario where the balance calculation produces results that are completely outside the expected operational range, effectively enabling arbitrary balance manipulation.
The operational impact of this vulnerability extends far beyond simple balance manipulation, creating a fundamental threat to the token's economic model and user trust. An attacker with owner access can arbitrarily set any user's balance to any value, including extremely large numbers that could potentially overflow the system or zero values that could be used to effectively drain user accounts. This capability allows for the creation of unlimited tokens or the manipulation of token distributions in ways that directly violate the contract's intended behavior and the token's economic principles. The vulnerability essentially grants the owner complete control over the token distribution mechanism, undermining the decentralized and trustless nature that Ethereum tokens are designed to provide.
The exploitation of this vulnerability follows patterns consistent with ATT&CK technique T1548.005, which involves privilege escalation through the manipulation of system or application functions. In this case, the attacker leverages their privileged position as contract owner to manipulate core token functions rather than attempting to gain ownership through external attacks. The implications for the broader Ethereum ecosystem are significant, as such vulnerabilities can lead to loss of funds for users, undermine confidence in smart contract implementations, and potentially impact the entire token economy built around the affected contract. The vulnerability demonstrates the critical importance of proper integer validation in smart contract development and the potential for seemingly minor implementation flaws to create catastrophic security implications.
Mitigation strategies for this vulnerability require immediate patching of the smart contract code to implement proper integer bounds checking and overflow protection mechanisms. The fix must ensure that all balance calculations within the mintToken function include proper validation to prevent integer overflow conditions, typically through the use of safe math libraries or explicit bounds checking. Additionally, the contract should implement comprehensive access control measures to ensure that only authorized parties can execute mint operations, and that all minting activities are properly logged and auditable. Regular security audits and formal verification of smart contract code should be implemented as standard practice to identify and prevent similar vulnerabilities in future deployments. The incident underscores the necessity of following established security frameworks and best practices in smart contract development, including the implementation of robust input validation and the use of proven security libraries to prevent integer overflow conditions.