CVE-2018-13719 in BiteduToken
Summary
by MITRE
The mintToken function of a smart contract implementation for BiteduToken, 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-2018-13719 represents a critical integer overflow flaw within the mintToken function of the BiteduToken smart contract implementation on the Ethereum blockchain. This vulnerability stems from improper input validation and arithmetic operations that fail to account for the finite nature of integer data types in smart contract environments. The flaw allows the contract owner to manipulate token balances through deliberate overflow conditions, creating a fundamental security breach that undermines the integrity of the token economy.
The technical implementation of this vulnerability occurs within the mintToken function where the smart contract fails to properly validate or constrain the parameters passed to the token minting process. When the owner invokes this function with specific parameters, the integer arithmetic operations can exceed the maximum value that can be represented by the underlying data type, causing an overflow condition. This overflow results in the balance of any specified user account being set to an arbitrary value determined by the attacker, effectively allowing unlimited minting of tokens beyond the intended contract parameters.
The operational impact of this vulnerability extends far beyond simple financial manipulation, as it fundamentally compromises the trust model that underpins blockchain-based token systems. An attacker with owner privileges can manipulate token distributions to create artificial scarcity, manipulate exchange rates, or even drain the contract of its entire token supply. The vulnerability also creates potential for gaming the token economy, as the attacker can set balances to values that may cause other contract functions to behave unexpectedly or fail entirely. This type of vulnerability directly violates the principle of immutability that is central to blockchain security and can lead to complete loss of funds for other token holders who rely on the contract's integrity.
The vulnerability aligns with CWE-190, Integer Overflow or Wraparound, which specifically addresses situations where integer arithmetic operations produce results that exceed the maximum value representable by the data type. From an adversarial perspective, this flaw maps to several ATT&CK techniques including privilege escalation through code injection and resource hijacking via manipulation of contract state. The attack vector is particularly dangerous because it requires only owner-level access, which suggests poor access control mechanisms within the contract implementation. Mitigation strategies should include implementing proper input validation, utilizing safe arithmetic libraries, and conducting comprehensive code audits that specifically target integer overflow conditions in all arithmetic operations. Additionally, the contract should implement proper access control measures and consider using established token standard implementations that have been audited for such vulnerabilities.
The broader implications of this vulnerability highlight the critical importance of thorough security testing and code review processes in smart contract development. This flaw demonstrates how seemingly simple functions can contain critical security vulnerabilities that can be exploited to gain unauthorized control over entire token economies. The vulnerability also underscores the need for developers to understand the specific security implications of blockchain environments, where the consequences of mathematical errors can be catastrophic. Organizations deploying smart contracts must implement robust security controls including formal verification processes, comprehensive testing protocols, and regular security audits to prevent similar vulnerabilities from compromising their token systems. The incident serves as a reminder that blockchain security requires a fundamental shift in development practices to account for the unique threat landscape and immutable nature of smart contract code.