CVE-2018-14003 in WeMediaChain
Summary
by MITRE
An integer overflow vulnerability exists in the function batchTransfer of WeMediaChain (WMC), an Ethereum token smart contract. An attacker could use it to set any user's balance.
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Analysis
by VulDB Data Team • 03/04/2020
The integer overflow vulnerability identified in CVE-2018-14003 represents a critical flaw within the WeMediaChain (WMC) Ethereum token smart contract implementation. This vulnerability specifically affects the batchTransfer function, which is designed to facilitate multiple token transfers in a single transaction. The flaw stems from improper input validation and arithmetic operations that fail to account for the maximum limits of integer data types, creating a pathway for malicious actors to manipulate token balances. Such vulnerabilities fall under the CWE-190 category of integer overflow and under the ATT&CK framework's software exploitation techniques, specifically targeting smart contract execution environments. The vulnerability exists at the core level of the contract's mathematical operations, where the system does not properly validate or constrain the values used in arithmetic calculations.
The technical exploitation of this vulnerability occurs when an attacker manipulates the parameters passed to the batchTransfer function, causing integer overflow conditions that result in unexpected behavior. When the contract processes these malformed inputs, the arithmetic operations exceed the maximum value that can be represented by the integer data type, leading to wraparound behavior. This wraparound allows attackers to effectively bypass normal balance checks and manipulation constraints, enabling them to set arbitrary user balances within the token ecosystem. The flaw demonstrates poor defensive programming practices and inadequate boundary checking mechanisms that are fundamental requirements for secure smart contract development. The vulnerability's impact extends beyond simple balance manipulation as it fundamentally compromises the integrity of the token's accounting system, potentially affecting all users within the contract's scope.
The operational impact of this vulnerability creates significant risks for the WeMediaChain ecosystem and its users. An attacker with knowledge of this flaw can manipulate token distributions, potentially creating unlimited tokens or setting negative balances, which would destabilize the entire token economy. The vulnerability also presents risks for automated systems that rely on accurate balance information, as the manipulation could cause cascading failures in dependent applications. From a security perspective, this flaw represents a severe threat to trust in the token's integrity and could lead to financial losses for users who hold WMC tokens. The vulnerability's exploitation does not require sophisticated techniques, making it particularly dangerous as it can be leveraged by attackers with basic knowledge of smart contract vulnerabilities. The issue also highlights the importance of comprehensive testing and formal verification in smart contract development, as such flaws often remain undetected during standard code reviews.
Mitigation strategies for this vulnerability should focus on implementing proper integer bounds checking and using safe arithmetic operations within the smart contract code. Developers should employ overflow protection mechanisms such as require statements that validate input parameters before processing, ensuring that all arithmetic operations remain within acceptable ranges. The use of established libraries and frameworks that provide safe arithmetic operations can significantly reduce the risk of similar vulnerabilities. Additionally, comprehensive testing including fuzz testing and formal verification should be implemented to identify potential overflow conditions before deployment. From an organizational perspective, regular security audits and code reviews should be conducted to ensure adherence to secure coding practices. The vulnerability also underscores the need for continuous monitoring and updating of smart contract implementations, as new attack vectors may emerge that exploit similar weaknesses in the codebase. Implementing proper access controls and transaction validation mechanisms can further reduce the attack surface and limit the potential impact of such vulnerabilities.