CVE-2018-13661 in App
Summary
by MITRE
The mintToken function of a smart contract implementation for APP, 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 in CVE-2018-13661 represents a critical integer overflow flaw within the mintToken function of an Ethereum-based token smart contract implementation. This security weakness specifically affects the APP token smart contract where the owner possesses the ability to manipulate user balances through improper handling of integer arithmetic operations. The flaw stems from insufficient input validation and overflow protection mechanisms within the contract's code logic, creating a scenario where mathematical operations can exceed the maximum representable value for the data type being used.
The technical implementation of this vulnerability manifests through the mintToken function's failure to properly validate or constrain integer values during balance updates. When the contract processes token minting operations, the underlying arithmetic operations can overflow beyond their defined boundaries, allowing an attacker with owner privileges to manipulate the balance of any user account to arbitrary values. This integer overflow condition typically occurs when the contract performs operations on unsigned integers without proper overflow checks, enabling malicious actors to exploit the mathematical properties of fixed-width integer representations. The vulnerability directly maps to CWE-190, which classifies integer overflow conditions that can lead to unexpected behavior and security consequences.
The operational impact of this vulnerability extends beyond simple financial manipulation to potentially compromise the entire token ecosystem and user trust. An attacker with owner access can artificially inflate user balances to extremely high values, potentially enabling unauthorized spending or creating artificial market distortions. The vulnerability also represents a significant threat to the contract's integrity since it allows for unauthorized balance modifications that could affect the token's supply mechanisms, voting rights, or other functionality dependent on accurate balance tracking. This flaw fundamentally undermines the security assumptions of the smart contract and creates potential for financial loss or system manipulation that could affect all token holders and the broader Ethereum ecosystem.
Mitigation strategies for this vulnerability require immediate implementation of proper integer overflow protection mechanisms within the smart contract code. The recommended approach involves incorporating explicit overflow checks before any arithmetic operations, utilizing safe math libraries, or implementing require statements that validate input parameters and prevent operations that could result in overflow conditions. The solution should also include comprehensive access control reviews to ensure that only authorized entities can perform mintToken operations, and that all balance modifications are properly validated against reasonable limits. Organizations should implement thorough code auditing practices that specifically target integer handling and arithmetic operations, aligning with industry best practices such as those outlined in the Ethereum Smart Contract Security Best Practices framework and the OWASP Smart Contract Security Verification Standard. Additionally, regular security assessments and formal verification techniques should be employed to identify similar vulnerabilities across the entire smart contract ecosystem and prevent recurrence of such issues in future implementations.