CVE-2018-13070 in EncryptedToken
Summary
by MITRE
The mintToken function of a smart contract implementation for EncryptedToken (ECC), 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 • 02/24/2020
The vulnerability identified as CVE-2018-13070 resides within the EncryptedToken (ECC) smart contract implementation on the Ethereum blockchain, specifically within the mintToken function that governs token creation and distribution. This flaw represents a critical security weakness that directly impacts the contract's integrity and the fundamental trust model of the token ecosystem. The vulnerability manifests as an integer overflow condition that occurs when the mintToken function processes token minting operations, allowing unauthorized manipulation of user balances through controlled input parameters. The flaw fundamentally undermines the contract's ability to maintain accurate and secure token accounting, creating potential for significant financial loss and system compromise.
The technical implementation of this vulnerability stems from improper input validation and arithmetic operations within the mintToken function where the contract fails to adequately check for integer overflow conditions before performing balance updates. When an attacker exploits this weakness, they can manipulate the token supply by setting arbitrary user balances to predetermined values, effectively bypassing normal token distribution mechanisms. This integer overflow condition typically occurs when the contract performs arithmetic operations that exceed the maximum value that can be represented by the data type used for balance storage, allowing attackers to wrap around to extremely large or small values that can be leveraged to manipulate account balances. The vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions in software implementations, and represents a classic example of how improper boundary checking can lead to severe security consequences in blockchain environments.
The operational impact of this vulnerability extends far beyond simple balance manipulation, as it fundamentally compromises the security model of the EncryptedToken contract and potentially affects all users who hold or interact with the token. An attacker with access to the owner privileges can exploit this flaw to inflate their own token holdings or manipulate other users' balances, effectively creating an unlimited supply of tokens or redistributing existing supply in unauthorized ways. This vulnerability creates opportunities for financial fraud, market manipulation, and potential loss of funds for legitimate token holders. The impact is particularly severe in decentralized finance contexts where such vulnerabilities can be exploited to drain liquidity pools, manipulate token prices, or create artificial scarcity. The vulnerability also represents a significant threat to the overall trust model of the Ethereum ecosystem, as it demonstrates how seemingly minor implementation flaws can create substantial security risks that affect the entire blockchain infrastructure.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening of smart contract implementations. The primary fix involves implementing proper input validation and arithmetic overflow checks within the mintToken function to prevent unauthorized balance manipulation. Developers should utilize safe math libraries or implement explicit overflow detection mechanisms that validate all arithmetic operations before updating account balances. Additionally, contract owners should implement comprehensive access control measures and regular security audits to identify similar vulnerabilities. The remediation approach should follow established best practices for smart contract security as outlined in the Ethereum Smart Contract Security Best Practices guidelines and align with ATT&CK framework techniques related to smart contract exploitation. Regular code reviews and formal verification processes should be implemented to prevent similar vulnerabilities in future contract deployments, emphasizing the importance of rigorous testing and validation of all arithmetic operations in blockchain-based applications.