CVE-2018-13174 in CryptoABS
Summary
by MITRE
The mintToken function of a smart contract implementation for CryptoABS (ABS), 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-2018-13174 resides within the mintToken function of the CryptoABS smart contract implementation running on the Ethereum blockchain. This critical flaw represents a classic integer overflow vulnerability that fundamentally compromises the contract's ability to maintain accurate token balances. The vulnerability stems from improper input validation and arithmetic operations within the mintToken function, which fails to properly check for overflow conditions when processing token minting operations. The affected contract allows the owner to manipulate token balances without proper authorization, creating a severe security risk that undermines the entire token economy.
The technical implementation of this vulnerability manifests through the lack of overflow protection in arithmetic operations within the mintToken function. When the contract processes token minting requests, it performs calculations that can exceed the maximum value that can be represented by the underlying data types, causing the values to wrap around to zero or negative numbers. This behavior, classified under CWE-190 as integer overflow, enables an attacker with owner privileges to manipulate the balance of any user account within the contract. The vulnerability specifically affects the uint256 data type operations where no bounds checking is performed during arithmetic operations, allowing for malicious manipulation of token supply and user balances.
The operational impact of this vulnerability extends far beyond simple balance manipulation, as it fundamentally breaks the trust model that underpins cryptocurrency systems. An attacker with owner access can arbitrarily inflate or deflate user balances, potentially creating infinite token supply conditions or zeroing out user holdings entirely. This vulnerability directly impacts the contract's integrity and can lead to complete loss of funds for users, as well as undermine confidence in the entire token ecosystem. The consequences include potential financial losses for token holders, contract value manipulation, and the possibility of creating artificial market conditions that could be exploited for profit. From an attacker's perspective, this vulnerability represents a high-value target that can be exploited to gain control over substantial token holdings and potentially manipulate market dynamics.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security improvements in smart contract development practices. The primary fix involves implementing proper overflow protection mechanisms using Solidity's built-in overflow checking features or manual bounds checking before arithmetic operations. Developers should utilize safe math libraries that automatically handle overflow conditions, ensuring that all arithmetic operations within token contracts are protected against integer overflow scenarios. Additionally, implementing comprehensive input validation and access control measures can prevent unauthorized manipulation of the mintToken function. The vulnerability also highlights the importance of thorough code review processes and formal verification techniques for smart contracts, as outlined in the ATT&CK framework's software development practices. Regular security audits and the adoption of security-focused development methodologies can help prevent similar vulnerabilities from being introduced into future contract implementations, emphasizing the need for robust security controls throughout the entire development lifecycle.