CVE-2018-13693 in GreenEnergyToken
Summary
by MITRE
The mintToken function of a smart contract implementation for GreenEnergyToken, 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 • 02/28/2020
The vulnerability identified as CVE-2018-13693 resides within the mintToken function of the GreenEnergyToken smart contract implementation running on the Ethereum blockchain. This critical flaw represents an integer overflow vulnerability that fundamentally compromises the contract's ability to maintain accurate token balances. The vulnerability stems from improper input validation and arithmetic operations within the mintToken function, which fails to properly check for overflow conditions when processing token minting operations. The integer overflow occurs when the contract attempts to increment token balances beyond the maximum value that can be represented by the underlying data type, allowing an attacker to manipulate the arithmetic operations in ways that produce unexpected results.
The technical exploitation of this vulnerability enables the contract owner to manipulate token balances in arbitrary user accounts by leveraging the integer overflow condition during the mintToken function execution. When the function processes token minting operations without proper overflow checks, it creates opportunities for attackers to craft specific inputs that cause the balance arithmetic to wrap around to unintended values. This behavior directly violates the fundamental principles of secure smart contract development and represents a classic example of improper integer handling in blockchain environments. The vulnerability operates at the core of the contract's token distribution mechanism, allowing malicious actors to either inflate or deflate user balances beyond normal operational parameters.
The operational impact of this vulnerability extends far beyond simple balance manipulation, as it fundamentally undermines the integrity and trustworthiness of the entire token ecosystem. An attacker with access to the contract owner privileges can arbitrarily set user balances to any value, including potentially infinite amounts, which could result in massive financial losses for the token ecosystem. The vulnerability affects the core accounting mechanisms of the token, potentially enabling unauthorized token creation, balance manipulation, and disruption of the token's economic model. This flaw directly impacts the security model of the GreenEnergyToken and could lead to complete loss of user funds or manipulation of token supply dynamics, making the entire system vulnerable to exploitation.
Mitigation strategies for this vulnerability must address the root cause through comprehensive code review and implementation of proper integer overflow protections. The primary remediation involves adding explicit overflow checks before any arithmetic operations within the mintToken function, utilizing safe math libraries or built-in overflow protection mechanisms available in modern Solidity versions. The contract should implement proper input validation and boundary checking to prevent arithmetic operations from exceeding maximum representable values. Additionally, the implementation should follow established security best practices such as those outlined in the CWE-190 category for integer overflow conditions and align with the ATT&CK framework's system security weaknesses. Regular security audits and formal verification processes should be implemented to identify similar vulnerabilities in other contract functions and ensure ongoing protection against similar integer overflow scenarios that could compromise the token's integrity and user trust.