CVE-2018-13541 in CryptoLeu
Summary
by MITRE
The mintToken function of a smart contract implementation for CryptoLeu, 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-2018-13541 resides within the mintToken function of CryptoLeu, an Ethereum-based token smart contract implementation. This flaw represents a critical integer overflow vulnerability that fundamentally compromises the contract's integrity and security model. The vulnerability manifests when the mintToken function processes token minting operations, allowing the contract owner to manipulate user balances beyond normal operational parameters. The technical nature of this vulnerability stems from improper input validation and arithmetic overflow handling within the smart contract's code execution flow.
The integer overflow occurs when the mintToken function performs arithmetic operations without adequate bounds checking or overflow protection mechanisms. This allows the contract owner to manipulate the balance calculation in such a way that arbitrary user balances can be set to any desired value, including potentially maliciously large amounts. The vulnerability specifically affects the token distribution mechanism and enables the contract owner to essentially create unlimited tokens or manipulate existing token holdings. This flaw directly violates the fundamental principles of secure smart contract development as outlined in the CWE-190 category for integer overflow vulnerabilities. The operational impact is severe as it allows for complete control over token distribution and can result in unauthorized token creation or manipulation of user accounts.
From an operational security perspective, this vulnerability creates a significant risk for all users of the CryptoLeu token as it enables the contract owner to perform unauthorized balance modifications. The attack vector is particularly dangerous because it requires no external interaction from users and operates entirely within the contract's privileged owner functions. The vulnerability can be exploited to create infinite token supply, manipulate token prices, or perform other malicious operations that undermine the token's economic model. This type of vulnerability aligns with ATT&CK technique T1499.004 for resource hijacking and represents a direct violation of the principle of least privilege in smart contract design. The exploitability of this vulnerability is high as it requires only owner-level access to the contract, which is typically a single private key or multisignature wallet.
Mitigation strategies for CVE-2018-13541 require immediate patching of the smart contract code to implement proper integer overflow protections. The fix must include comprehensive input validation, bounded arithmetic operations, and proper overflow checking mechanisms before any balance modifications occur. Developers should implement the SafeMath library or similar arithmetic protection mechanisms to prevent integer overflows. Additionally, contract owners should conduct thorough security audits and consider implementing multi-signature ownership controls to reduce the risk of unauthorized access. The vulnerability demonstrates the critical importance of formal verification and security testing in smart contract development, as outlined in industry standards for blockchain security practices. Regular security assessments and code reviews should be mandatory for all smart contract implementations to prevent similar vulnerabilities from being introduced in future deployments.