CVE-2018-13667 in UTBTokenTest
Summary
by MITRE
The mintToken function of a smart contract implementation for UTBTokenTest, 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.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 02/28/2020
The vulnerability identified as CVE-2018-13667 represents a critical integer overflow flaw within the mintToken function of the UTBTokenTest Ethereum token smart contract implementation. This vulnerability stems from improper input validation and arithmetic operations that fail to account for the maximum limits of integer data types. The flaw allows the contract owner to manipulate token balances in ways that could lead to significant financial loss and system compromise. The integer overflow occurs when the mintToken function performs arithmetic operations without proper boundary checks, enabling an attacker with owner privileges to execute malicious balance manipulations that exceed normal token supply limits.
The technical execution of this vulnerability relies on the specific implementation details of the smart contract's arithmetic handling and the lack of overflow protection mechanisms. When the owner invokes the mintToken function with carefully crafted parameters, the integer overflow allows the balance calculation to wrap around to an unintended value, effectively enabling the creation of arbitrary token balances for any user address. This type of vulnerability falls under the CWE-190 category of integer overflow/underflow, which is classified as a fundamental weakness in software design that occurs when an integer operation exceeds the maximum or minimum value that can be represented by the data type. The vulnerability is particularly dangerous because it operates within the permissioned context of contract ownership, meaning that only the designated owner can exploit it, but the consequences can be devastating for token holders and the overall ecosystem.
The operational impact of this vulnerability extends beyond simple balance manipulation to potentially compromise the entire token economy and trust in the smart contract system. An attacker with owner privileges could theoretically inflate token supplies indefinitely, manipulate user balances to create artificial wealth distributions, or even cause the token to become worthless through strategic balance manipulation. The vulnerability creates a pathway for financial fraud and could lead to complete loss of funds for token holders who rely on the integrity of the contract's balance management. This type of flaw directly impacts the core security principles of blockchain systems, particularly the immutability and integrity guarantees that users expect from smart contracts. The vulnerability's exploitation could result in significant market disruption and regulatory scrutiny for the affected token project.
Mitigation strategies for this vulnerability must focus on implementing proper integer overflow protection mechanisms throughout the smart contract codebase. The recommended approach involves incorporating explicit boundary checks before any arithmetic operations, utilizing safe math libraries that automatically handle overflow conditions, and implementing comprehensive input validation for all functions that manipulate token balances. Additionally, contract owners should consider implementing multi-signature authorization mechanisms for critical functions like mintToken to reduce the risk of single points of failure. The solution should align with industry best practices outlined in the Ethereum Smart Contract Security Best Practices guidelines and should incorporate defensive programming techniques that prevent integer overflow conditions. Regular security audits and formal verification processes should be implemented to identify similar vulnerabilities in other contract functions and to ensure that all arithmetic operations are properly protected against overflow and underflow conditions. The vulnerability also highlights the importance of following the principle of least privilege and implementing robust access control mechanisms to prevent unauthorized manipulation of critical contract functions.