CVE-2018-13692 in MehdiTAZIToken
Summary
by MITRE
The mintToken function of a smart contract implementation for MehdiTAZIToken, 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 as CVE-2018-13692 represents a critical integer overflow flaw within the mintToken function of the MehdiTAZIToken smart contract deployed on the Ethereum blockchain. This vulnerability stems from inadequate input validation and arithmetic overflow handling within the contract's token minting mechanism, creating a fundamental security weakness that directly impacts the contract's integrity and user asset protection. The flaw allows the contract owner to manipulate token balances of arbitrary users by exploiting the overflow condition, effectively bypassing normal token distribution and transfer restrictions. Such a vulnerability fundamentally undermines the trustless nature of blockchain-based token systems and exposes users to potential financial loss.
The technical implementation of this vulnerability resides in the mintToken function where integer overflow occurs during balance calculations, specifically when adding new tokens to existing user balances. The contract fails to validate that the resulting balance value does not exceed the maximum value that can be represented by the underlying data type, typically a 256-bit unsigned integer in Ethereum smart contracts. This overflow condition creates a scenario where arithmetic operations can wrap around to zero or extremely large values, enabling the contract owner to manipulate user balances beyond normal operational parameters. The vulnerability is classified under CWE-190 as an integer overflow condition, which represents a well-documented weakness in software systems where integer arithmetic operations exceed the maximum representable value. The flaw exists in the contract's logic flow where no overflow checks are performed before balance updates, making it susceptible to malicious manipulation by the contract owner.
The operational impact of this vulnerability extends beyond simple balance manipulation to encompass potential financial fraud and contract compromise. An attacker with owner privileges can artificially inflate or deflate user balances, potentially creating infinite token supply scenarios or zeroing out user holdings entirely. This capability enables the contract owner to drain user funds, create artificial market manipulation conditions, or establish unauthorized token distributions that bypass normal protocol governance mechanisms. The vulnerability particularly affects the token's fungibility and the security assumptions users make when interacting with the contract, as it allows for arbitrary balance manipulation that could be exploited for financial gain. The implications are severe for token holders who rely on the contract's integrity for their asset security, as the vulnerability provides a direct path for unauthorized balance modification that cannot be easily detected or reversed.
Mitigation strategies for this vulnerability require immediate contract auditing and potential redeployment with proper overflow protection mechanisms. The recommended approach involves implementing explicit overflow checks using Solidity's built-in overflow protection features or manual validation before balance updates. The contract should enforce bounds checking on all arithmetic operations involving user balances, ensuring that additions and subtractions do not exceed maximum integer values. Additionally, the contract owner should implement proper access controls and consider using openzeppelin's SafeMath library to provide automated overflow protection for arithmetic operations. The vulnerability demonstrates the critical importance of secure coding practices in smart contract development, particularly regarding integer arithmetic and user balance management. Organizations should also consider implementing regular security audits and formal verification processes to identify similar vulnerabilities before deployment. This incident highlights the necessity for comprehensive testing procedures including fuzz testing and boundary condition analysis to prevent similar vulnerabilities in future smart contract implementations. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques where an attacker with owner privileges can manipulate system state through arithmetic manipulation, emphasizing the need for robust access control and validation mechanisms in blockchain applications.