CVE-2018-13327 in ChuCunLingAIGO
Summary
by MITRE • 01/25/2023
The transfer and transferFrom functions of a smart contract implementation for ChuCunLingAIGO (CCLAG), an Ethereum token, have an integer overflow.
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Analysis
by VulDB Data Team • 08/05/2024
The vulnerability identified as CVE-2018-13327 affects the ChuCunLingAIGO (CCLAG) Ethereum token smart contract implementation, specifically targeting the transfer and transferFrom functions. This represents a critical security flaw that fundamentally compromises the integrity of the token's transfer mechanisms and poses significant financial risks to users and the broader Ethereum ecosystem. The vulnerability stems from improper handling of integer arithmetic operations within the smart contract code, creating a scenario where mathematical operations can exceed the maximum representable value for the data type being used.
The technical flaw manifests as an integer overflow condition in the transfer functions of the CCLAG token contract. When the transfer or transferFrom functions process token amounts that exceed the maximum value that can be stored in the designated integer data type, the value wraps around to zero or a negative value due to the underlying binary representation behavior. This overflow occurs because the smart contract implementation lacks proper validation checks before performing arithmetic operations on user-supplied token amounts. The vulnerability is classified as a CWE-190: Integer Overflow or Wraparound, which is a well-documented weakness in software development that particularly affects blockchain smart contracts where financial transactions are involved. The flaw allows malicious actors to manipulate token balances and potentially drain funds from user accounts or the contract itself.
The operational impact of this vulnerability extends beyond simple financial loss to encompass broader systemic risks within the Ethereum token ecosystem. An attacker who exploits this integer overflow can manipulate the token transfer process to either create unlimited tokens or bypass transfer restrictions entirely. This creates opportunities for unauthorized fund transfers, account manipulation, and potentially complete contract compromise. The vulnerability affects all users who interact with the CCLAG token through the affected smart contract, making it particularly dangerous as it impacts the fundamental trust model of the token. The flaw also demonstrates the critical importance of proper input validation and arithmetic operation handling in smart contract development, as similar vulnerabilities have been exploited across multiple blockchain platforms to cause significant financial damage.
Mitigation strategies for this vulnerability require immediate contract deployment updates to address the integer overflow conditions. The recommended approach involves implementing proper bounds checking before any arithmetic operations in the transfer functions, utilizing safe math libraries that prevent overflow conditions, and conducting comprehensive code reviews to identify similar issues in other contract functions. Security measures should include validating input parameters against maximum integer limits, implementing proper error handling for arithmetic operations, and utilizing established secure coding practices for blockchain development. Organizations should also consider implementing additional monitoring systems to detect anomalous transfer patterns that might indicate exploitation attempts. The vulnerability highlights the necessity of following established security frameworks and best practices such as those outlined in the Ethereum Smart Contract Security Best Practices guidelines, which emphasize the importance of thorough testing and validation of all mathematical operations within smart contracts to prevent similar issues from occurring in future implementations.