CVE-2018-13527 in ElevateCoin
Summary
by MITRE
The mintToken function of a smart contract implementation for ElevateCoin, 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-2018-13527 represents a critical integer overflow flaw within the mintToken function of ElevateCoin's Ethereum smart contract implementation. This security weakness stems from improper input validation and arithmetic operations that fail to account for maximum value limits inherent in integer data types. The vulnerability specifically affects the token contract's ability to manage user balances, creating a scenario where the contract owner can manipulate account balances without proper authorization. The flaw manifests when the mintToken function processes token minting operations, allowing for arithmetic overflow conditions that can result in unintended balance modifications.
The technical execution of this vulnerability relies on the contract owner exploiting the lack of overflow checks during arithmetic operations within the mintToken function. When the function performs calculations that exceed the maximum representable value for the integer data type used, the overflow occurs and produces unexpected results. This behavior enables the malicious actor to set any user's balance to an arbitrary value, effectively bypassing normal token distribution and transfer mechanisms. The vulnerability operates at the core level of the token contract's balance management system, where the owner's privileges are incorrectly scoped to allow such destructive operations.
From an operational impact perspective, this vulnerability creates severe consequences for the token ecosystem and its users. The ability to arbitrarily set user balances compromises the fundamental integrity of the token economy, potentially leading to massive financial losses for token holders. The vulnerability undermines trust in the smart contract system and can result in the creation of unlimited tokens or manipulation of account balances in ways that benefit the attacker while harming legitimate users. Additionally, the flaw affects the contract's overall security posture by providing an attack vector that allows for unauthorized balance manipulation without detection.
The vulnerability aligns with CWE-190, Integer Overflow or Wraparound, which specifically addresses issues where integer arithmetic operations exceed the maximum representable value. This weakness falls under the broader category of smart contract security flaws that have been extensively documented in the blockchain security community. The attack pattern follows principles outlined in the MITRE ATT&CK framework for blockchain environments, particularly focusing on smart contract manipulation and privilege escalation techniques. Organizations should implement comprehensive input validation, utilize safe arithmetic libraries, and conduct thorough code reviews to prevent similar vulnerabilities in their blockchain applications.
Mitigation strategies for CVE-2018-13527 require immediate patching of the smart contract implementation with proper overflow checks and validation mechanisms. The mintToken function must incorporate bounds checking to prevent arithmetic operations from exceeding maximum integer values, ensuring that all balance modifications remain within valid ranges. Additionally, implementing proper access controls and privilege management can help limit the scope of operations that can manipulate user balances. Regular security audits and formal verification processes should be established to identify and remediate similar vulnerabilities before they can be exploited by malicious actors. The use of established smart contract development frameworks that include built-in overflow protection mechanisms can significantly reduce the risk of such vulnerabilities occurring in future implementations.