CVE-2018-13069 in Dychain
Summary
by MITRE
The mintToken function of a smart contract implementation for DYchain (DYC), 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 • 02/24/2020
The vulnerability identified as CVE-2018-13069 resides within the mintToken function of the DYchain (DYC) smart contract implementation deployed on the Ethereum blockchain. This flaw represents a critical integer overflow vulnerability that fundamentally compromises the contract's integrity and tokenomics. The vulnerability manifests when the mintToken function processes token minting operations without proper overflow checks, allowing malicious actors with owner privileges to manipulate token balances arbitrarily. The root cause of this issue aligns with CWE-190, which specifically addresses integer overflow conditions where operations on signed or unsigned integers exceed their maximum representable values. Such vulnerabilities in blockchain smart contracts can have devastating consequences as they directly impact the fundamental principles of decentralized finance and token governance.
The technical exploitation of this vulnerability occurs through the mintToken function's failure to validate input parameters and perform boundary checks on token amounts before updating user balances. When an attacker with owner access invokes this function, they can manipulate the internal accounting system to set any user's token balance to an arbitrary value, effectively enabling them to create unlimited tokens or manipulate existing balances. This type of vulnerability falls under the ATT&CK framework's T1548.001 technique, which involves privilege escalation through manipulation of system or application code. The flaw essentially allows for unauthorized token creation and distribution, bypassing normal minting restrictions and potentially leading to massive dilution of token value or complete system compromise.
The operational impact of CVE-2018-13069 extends far beyond simple financial loss, as it fundamentally undermines trust in the smart contract system and the underlying blockchain infrastructure. Users who hold DYchain tokens may experience immediate devaluation of their holdings due to unauthorized minting, while the entire ecosystem faces potential collapse if the vulnerability is exploited maliciously. The vulnerability also creates a persistent risk for the contract's long-term stability, as any user with owner privileges can exploit this flaw at any time, making it particularly dangerous in decentralized environments where trust assumptions are critical. The implications for blockchain security are severe, as this type of vulnerability demonstrates how seemingly minor implementation flaws can create catastrophic consequences for entire token economies.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security architecture improvements. The primary fix involves implementing proper integer overflow checks within the mintToken function, ensuring that all arithmetic operations include boundary validation before updating balances. This requires adding explicit checks to verify that token amounts do not exceed maximum integer limits and that the resulting balances remain within valid ranges. Additionally, implementing comprehensive access control mechanisms and multi-signature requirements for owner privileges can significantly reduce the risk of exploitation. The solution should also incorporate regular security audits and formal verification techniques to identify similar vulnerabilities across the entire smart contract codebase. Organizations should also consider implementing time-based access controls and transaction monitoring systems to detect anomalous minting activities that might indicate exploitation attempts.