CVE-2018-13073 in ETHEREUMBLACK
Summary
by MITRE
The mintToken function of a smart contract implementation for ETHEREUMBLACK (ETCBK), 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 • 02/24/2020
The vulnerability identified as CVE-2018-13073 represents a critical integer overflow flaw within the mintToken function of the EthereumBLACK (ETCBK) token smart contract implementation. This vulnerability stems from improper input validation and arithmetic handling within the contract's codebase, creating a scenario where the contract owner can manipulate user balances arbitrarily. The flaw exists at the core of the token's issuance mechanism, where the mintToken function fails to properly validate or constrain the values being processed during token creation operations.
The technical exploitation of this vulnerability occurs through the manipulation of integer arithmetic operations within the smart contract's mintToken function. When the contract owner invokes this function, they can specify arbitrary values for token minting that exceed the maximum limits of the integer data types used in the implementation. This overflow condition allows the owner to bypass normal balance constraints and directly set any user's token balance to an arbitrary value, effectively enabling unlimited token creation or manipulation of existing balances. The vulnerability is classified under CWE-190 as an integer overflow condition, specifically manifesting as an unsigned integer overflow that can lead to unexpected behavior in the contract's state management.
The operational impact of this vulnerability extends far beyond simple balance manipulation, as it fundamentally compromises the integrity and security of the entire token ecosystem. An attacker with owner privileges can exploit this flaw to create unlimited tokens, manipulate market dynamics, or potentially drain funds from other users' accounts. The implications are severe for token holders and investors who rely on the contract's integrity for their digital asset security. This vulnerability undermines trust in the smart contract implementation and can lead to significant financial losses for the token ecosystem. The vulnerability affects all users of the ETCBK token who interact with the contract, as the malicious behavior is initiated by the contract owner rather than external parties.
Mitigation strategies for this vulnerability require immediate remediation of the smart contract code through proper integer overflow protection mechanisms. The implementation should incorporate explicit bounds checking and validation of input parameters within the mintToken function to prevent arithmetic overflow conditions. Security measures should include the use of safe math libraries or explicit overflow detection routines that validate all arithmetic operations before execution. Additionally, the contract owner should implement proper access controls and audit trails to monitor any mintToken function calls. The remediation process should involve comprehensive code review and testing to ensure that all integer operations within the contract are properly constrained and validated. This vulnerability highlights the critical importance of secure smart contract development practices and adherence to established security standards in blockchain-based systems. Organizations should implement continuous security monitoring and regular code audits to identify and address similar vulnerabilities in their smart contract implementations. The ATT&CK framework categorizes this as a privilege escalation technique where an attacker with elevated privileges can manipulate contract state through arithmetic manipulation.