CVE-2018-13766 in Easticoin
Summary
by MITRE
The mintToken function of a smart contract implementation for Easticoin, 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 • 03/03/2020
The vulnerability identified in CVE-2018-13766 represents a critical integer overflow flaw within the mintToken function of Easticoin smart contract implementation, exposing the token ecosystem to significant financial risks. This vulnerability falls under the CWE-190 category of integer overflow and under the ATT&CK technique T1210 for exploitation of remote services through privilege escalation. The flaw specifically affects the token contract's ability to manage user balances through the mintToken function, which is typically designed to create new tokens and distribute them to designated addresses. The integer overflow occurs when the contract attempts to increment a token balance beyond the maximum value that can be represented by the underlying data type, causing the value to wrap around to zero or a negative number, thereby allowing unauthorized manipulation of account balances.
The technical exploitation of this vulnerability enables the contract owner to manipulate token balances in ways that bypass normal transactional constraints and security mechanisms inherent to the Ethereum blockchain. When the mintToken function processes a request to mint new tokens for a specific user, the integer overflow allows the owner to specify an arbitrary balance value that exceeds the normal limits of the token accounting system. This creates a scenario where the owner can effectively create unlimited tokens or manipulate existing balances to arbitrary values, potentially leading to massive inflation of the token supply or unauthorized access to funds. The vulnerability is particularly concerning because it operates at the core of token distribution mechanisms and can be exploited without requiring complex attack vectors or additional privileges beyond those already granted to the contract owner.
The operational impact of this vulnerability extends beyond simple financial manipulation to encompass potential systemic risks within the Easticoin ecosystem and broader implications for smart contract security practices. Users who hold Easticoin tokens face potential loss of funds as malicious actors could exploit this vulnerability to drain accounts or create artificial scarcity by manipulating balances. The vulnerability undermines trust in the token's integrity and the underlying smart contract implementation, potentially causing market instability and regulatory scrutiny. Furthermore, the exploitability of this vulnerability demonstrates a fundamental flaw in the contract's input validation and boundary checking mechanisms, which are essential components of secure smart contract development as outlined in the Ethereum Smart Contract Security Best Practices and the OpenZeppelin security guidelines. The integer overflow represents a failure to implement proper overflow protection mechanisms that are standard practice in secure software development and blockchain contract design.
Mitigation strategies for CVE-2018-13766 require immediate remediation of the smart contract code through comprehensive input validation and the implementation of overflow protection mechanisms. The primary solution involves adding proper boundary checks to ensure that token minting operations cannot exceed the maximum representable values for the data types used in balance calculations. Developers should implement require statements that validate input parameters and use safe arithmetic operations that prevent overflow conditions. Additionally, the contract should undergo comprehensive security auditing to identify similar vulnerabilities in other functions and ensure that all mathematical operations are properly protected. The fix should include thorough testing of edge cases and boundary conditions to verify that the mintToken function behaves correctly under all circumstances. Organizations should also consider implementing access control mechanisms that limit the ability to perform token minting operations to trusted parties only, and establish regular security review processes to identify and remediate similar vulnerabilities before they can be exploited. The vulnerability serves as a critical reminder of the importance of proper input validation and the necessity of following established security frameworks such as the OWASP Smart Contract Security Verification Standard and the SEC's guidelines for blockchain-based asset security.