CVE-2018-13687 in normikaivo
Summary
by MITRE
The mintToken function of a smart contract implementation for normikaivo, 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.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/28/2020
The vulnerability identified in CVE-2018-13687 represents a critical integer overflow flaw within the mintToken function of an Ethereum-based smart contract implementation known as normikaivo. 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 management capabilities. The flaw allows the contract owner to manipulate user balances arbitrarily, effectively compromising the token economy and user trust in the system. Such vulnerabilities are particularly dangerous in decentralized applications where smart contracts govern financial assets and user interactions.
The technical implementation of this vulnerability resides in the mintToken function's failure to properly validate or constrain integer values during balance calculations and updates. When the owner invokes this function, the contract performs arithmetic operations without adequate overflow checks that would normally prevent values from exceeding the maximum limits of the data types used. This creates a scenario where the owner can manipulate the balance of any user account to an arbitrary value, effectively allowing for unauthorized fund manipulation and potential theft of tokens. The vulnerability is classified as a CWE-191 Integer Underflow/Overflow, which represents a well-documented weakness in software development where arithmetic operations exceed the maximum or minimum values that can be represented by the data type. This particular implementation flaw allows for direct manipulation of the token supply and user account balances through a privileged function call.
The operational impact of this vulnerability extends beyond simple balance manipulation to encompass broader threats to the entire token ecosystem. An attacker with owner privileges can essentially create unlimited tokens or drain accounts of their holdings, fundamentally compromising the token's value proposition and the underlying blockchain's security model. Users who hold tokens in this system face potential loss of funds, while the smart contract's credibility and the trust in the entire platform are severely undermined. The vulnerability enables scenarios where the owner can create artificial token distributions or manipulate market dynamics, potentially leading to significant financial losses for users and investors. This type of flaw directly violates the core principles of blockchain security where transparency and immutability are expected, creating an environment where the contract owner can act as both judge and jury in the token economy.
Mitigation strategies for this vulnerability require immediate implementation of proper integer overflow protections within the smart contract code. The mintToken function must incorporate comprehensive input validation and arithmetic overflow checks using established Solidity security patterns such as SafeMath libraries or explicit boundary checks. Additionally, access controls should be carefully reviewed to ensure that privileged functions cannot be abused, and the contract should implement proper auditing mechanisms to track all balance modifications. The vulnerability demonstrates the critical importance of following secure coding practices in smart contract development, particularly the need for rigorous testing and code review processes. Organizations should also consider implementing multi-signature ownership models and regular security audits to prevent similar flaws from being introduced into smart contract implementations, as this vulnerability aligns with ATT&CK technique T1548.001 Privilege Escalation through the exploitation of contract ownership privileges. The incident underscores the necessity of adhering to security best practices in blockchain development and the importance of continuous monitoring and updating of smart contract systems to maintain their integrity and user confidence.