CVE-2018-13686 in ICO Dollar
Summary
by MITRE
The mintToken function of a smart contract implementation for ICO Dollar (ICOD), 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 in CVE-2018-13686 represents a critical integer overflow flaw within the mintToken function of the ICO Dollar smart contract implementation running on the Ethereum blockchain. This vulnerability stems from improper input validation and arithmetic operations that fail to account for boundary conditions in the token minting process. The flaw allows an attacker with owner privileges to manipulate token balances by exploiting the underlying integer overflow mechanism, effectively enabling arbitrary balance manipulation.
The technical exploitation of this vulnerability occurs through the mintToken function's handling of unsigned integer arithmetic operations. When the contract attempts to increment token balances or perform other arithmetic operations involving user balances, the lack of proper overflow checks enables attackers to wrap integer values beyond their maximum limits. This creates a scenario where the owner can manipulate the balance of any user account to an arbitrary value, potentially leading to unlimited token generation or balance manipulation. The vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions in software implementations.
The operational impact of this vulnerability extends beyond simple balance manipulation to potentially compromise the entire token economy and trust mechanisms within the ICO Dollar ecosystem. An attacker with owner access could artificially inflate their own token holdings while simultaneously manipulating other users' balances, leading to potential market manipulation, unfair distribution advantages, and complete control over the token supply. This vulnerability undermines the fundamental principles of blockchain tokenomics and smart contract security, as it allows for unauthorized control over token distribution and user account balances. The implications are particularly severe given that this affects an initial coin offering token where user trust and fair distribution are paramount.
Mitigation strategies for this vulnerability require immediate implementation of proper integer overflow protections within the smart contract code. The recommended approach involves utilizing safe arithmetic libraries or implementing explicit bounds checking before any arithmetic operations in the mintToken function. Additionally, contract owners should implement comprehensive access control mechanisms and regular security audits to prevent unauthorized access to privileged functions. The solution must align with established security frameworks such as the secure coding practices outlined in the OWASP Secure Coding Standards and the Ethereum Smart Contract Security Best Practices. Deployment of formal verification tools and comprehensive testing procedures including fuzz testing should be implemented to ensure that similar vulnerabilities are not present in other contract functions. The remediation process should also include a complete code review focusing on all arithmetic operations and integer handling within the contract to prevent analogous issues from persisting in the system.