CVE-2018-13182 in loncoin
Summary
by MITRE
The mintToken function of a smart contract implementation for loncoin (LON), 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 • 02/25/2020
The vulnerability identified in CVE-2018-13182 represents a critical integer overflow flaw within the mintToken function of the loncoin (LON) Ethereum token smart contract implementation. This vulnerability stems from inadequate input validation and overflow handling mechanisms within the contract's codebase, creating a scenario where the contract owner can manipulate user balances arbitrarily. The flaw specifically affects the token's minting functionality, which is designed to create new tokens and allocate them to user accounts. When the mintToken function processes token creation requests, it fails to properly validate the input parameters, particularly those related to balance calculations and value assignments. The integer overflow occurs during arithmetic operations that exceed the maximum value that can be represented within the designated data type, allowing malicious actors to exploit this weakness to manipulate token distributions. This vulnerability directly violates the fundamental principles of secure smart contract development and represents a clear violation of CWE-190, which addresses integer overflow and underflow conditions in software implementations. The security implications extend beyond simple balance manipulation as they fundamentally compromise the integrity and trustworthiness of the token ecosystem, potentially enabling the contract owner to drain funds or manipulate market dynamics through unauthorized balance adjustments.
The operational impact of this vulnerability is severe and multifaceted, affecting both the immediate token functionality and the broader ecosystem of users and exchanges that rely on the LON token. An attacker with access to the contract owner account can leverage this flaw to create unlimited tokens for specific user accounts, effectively allowing them to generate arbitrary balances without proper authorization or justification. This capability undermines the core economic model of the token, as it enables the contract owner to manipulate supply distribution, potentially creating artificial scarcity or abundance to manipulate token prices. The vulnerability also creates opportunities for financial manipulation and market disruption, as the attacker could potentially flood the market with tokens for specific accounts or conversely concentrate large holdings to influence trading dynamics. From a cybersecurity perspective, this vulnerability represents a high-severity risk that aligns with ATT&CK technique T1059.001, which involves executing malicious code through command injection or similar mechanisms. The flaw essentially allows for unauthorized code execution within the contract's logic, enabling the attacker to perform operations that should be restricted to authorized parties.
Mitigation strategies for CVE-2018-13182 must address both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities in future smart contract implementations. The primary fix involves implementing comprehensive input validation and overflow protection mechanisms within the mintToken function, including explicit checks for integer overflow conditions before any arithmetic operations are performed. Developers should employ modern Solidity practices such as using SafeMath libraries or enabling compiler features that automatically check for overflow conditions. The contract should validate all input parameters, particularly those related to balance calculations, ensuring that values remain within acceptable ranges and that arithmetic operations do not exceed data type limitations. Additionally, access controls should be strengthened to ensure that only authorized parties can invoke the mintToken function, and that all balance modifications are properly logged and auditable. Organizations should implement regular smart contract auditing processes that specifically target integer overflow vulnerabilities and other common security flaws. The remediation process should also include comprehensive testing of edge cases and boundary conditions to ensure that the fixed implementation handles all possible inputs correctly. Security teams should also establish monitoring protocols to detect any unauthorized balance modifications that might indicate exploitation attempts, and maintain detailed audit trails that can be used for forensic analysis if vulnerabilities are discovered. This vulnerability serves as a critical reminder of the importance of secure coding practices in blockchain environments where financial assets are at stake and where the immutable nature of smart contracts makes vulnerabilities particularly dangerous.