CVE-2018-13158 in AssetToken
Summary
by MITRE
The mintToken function of a smart contract implementation for AssetToken, 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 • 02/25/2020
The vulnerability identified as CVE-2018-13158 represents a critical integer overflow flaw within the mintToken function of an Ethereum smart contract implementation for AssetToken. This vulnerability stems from improper input validation and arithmetic operations that fail to account for the maximum limits of integer data types. The flaw allows an attacker with owner privileges to manipulate token balances by setting arbitrary values, effectively bypassing normal token minting and distribution mechanisms. Such a vulnerability directly impacts the fundamental integrity of the token economy and can lead to severe financial consequences for token holders and the broader ecosystem.
The technical execution of this vulnerability occurs through the mintToken function where integer overflow conditions are not properly handled. When the contract attempts to increment token balances or perform arithmetic operations on token amounts, the lack of overflow checks allows values to wrap around to zero or negative numbers. This creates a scenario where an attacker can manipulate the balance of any user account to an arbitrary value, potentially creating unlimited tokens or setting balances to malicious values that could disrupt the token's economic model. The vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions in software systems.
The operational impact of CVE-2018-13158 extends beyond simple balance manipulation to encompass potential financial loss, market disruption, and trust erosion within the token ecosystem. An attacker with owner access could inflate their own token holdings, manipulate market prices, or even create a scenario where the total supply of tokens becomes corrupted, rendering the entire token system unstable. This vulnerability particularly affects decentralized finance applications and token-based systems where trust in the underlying smart contract's integrity is paramount. The attack vector leverages the owner privileges typically granted during contract deployment, making it a high-severity issue that requires immediate attention.
Mitigation strategies for this vulnerability should include implementing comprehensive input validation and overflow protection mechanisms within the smart contract code. Developers must ensure that all arithmetic operations include proper bounds checking and that integer overflow conditions are explicitly handled through libraries or custom functions that prevent wrapping behavior. The remediation approach should align with established security practices such as using SafeMath libraries or similar overflow protection mechanisms that are widely adopted in the Ethereum ecosystem. Additionally, regular security audits and formal verification processes should be implemented to identify similar vulnerabilities in smart contract implementations. The vulnerability also demonstrates the importance of privilege separation and access control mechanisms, as the ability to manipulate token balances through owner functions highlights the need for robust governance structures within token systems. Organizations should implement multi-signature wallets and time locks for critical contract functions to reduce the risk of unauthorized access and exploitation of such vulnerabilities.