CVE-2018-13513 in Ubiou
Summary
by MITRE
The mintToken function of a smart contract implementation for Ubiou, 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 • 02/27/2020
The vulnerability identified as CVE-2018-13513 represents a critical integer overflow flaw within the mintToken function of Ubiou's Ethereum smart contract implementation. This vulnerability falls under the CWE-190 category of integer overflow and under the CWE-682 category of incorrect arithmetic operations, creating a significant security risk that directly impacts the contract's integrity and user funds. The flaw exists in the token contract's core functionality where the owner can manipulate user balances through improper handling of integer values during token minting operations.
The technical execution of this vulnerability occurs when the mintToken function processes token creation requests without proper bounds checking or overflow validation. When the contract attempts to increment a user's balance through arithmetic operations, the integer overflow allows an attacker with owner privileges to manipulate the calculation results in unexpected ways. This overflow can cause the balance value to wrap around to an unintended large number or even zero, enabling the contract owner to set arbitrary user balances to any desired value including potentially massive amounts or negative values that could be exploited.
The operational impact of this vulnerability extends beyond simple balance manipulation to potentially compromise the entire token economy and user trust in the Ubiou platform. An attacker with owner access can manipulate user balances to create artificial wealth distribution, potentially enabling fraudulent transactions or market manipulation. The vulnerability also creates a risk of contract state corruption where legitimate users may lose access to their tokens or face unexpected balance changes. This type of vulnerability directly violates the fundamental principles of blockchain security and trustless systems, as it allows privileged users to bypass normal tokenomics and user account management protocols.
Mitigation strategies for this vulnerability require immediate contract remediation through proper integer overflow protection mechanisms including the use of safe math libraries, bounds checking, and validation of all arithmetic operations before execution. The implementation should utilize modern Solidity versions that include built-in overflow protection or employ external libraries such as OpenZeppelin's SafeMath to prevent arithmetic overflows. Additionally, contract access controls should be reviewed to ensure that only authorized parties have owner privileges, and regular security audits should be conducted to identify similar vulnerabilities in other contract functions. This vulnerability demonstrates the critical importance of rigorous input validation and arithmetic operation safety in smart contract development, aligning with ATT&CK technique T1210 for exploitation of vulnerabilities and highlighting the need for secure coding practices in blockchain applications.