CVE-2018-13649 in Deploy
Summary
by MITRE
The mintToken function of a smart contract implementation for Deploy, 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 in CVE-2018-13649 represents a critical integer overflow flaw within the mintToken function of an Ethereum token smart contract deployed by the Deploy project. This vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, which occurs when an operation on integer values exceeds the maximum representable value for that data type. The specific implementation flaw allows the contract owner to manipulate token balances through improper handling of arithmetic operations that should have been protected against overflow conditions.
The technical execution of this vulnerability stems from the lack of proper input validation and overflow checking within the mintToken function. When the owner invokes this function with specific parameters, the arithmetic operations involved in calculating new token balances do not properly validate whether the resulting values would exceed the maximum limits of the integer data types used. This creates a scenario where an attacker with owner privileges can manipulate the balance of any user account to arbitrary values, effectively bypassing normal token minting and transfer restrictions.
The operational impact of this vulnerability is severe and multifaceted. An attacker who gains access to the contract owner account can instantly manipulate token distributions, create unlimited tokens, or drain existing token balances from other users. This vulnerability directly violates the fundamental principles of blockchain security and trustless systems, as it allows for unauthorized manipulation of token supply and user balances. The attack pattern aligns with ATT&CK technique T1059.001 for operating system command and script injection, though in this case it manifests through smart contract manipulation rather than traditional command execution.
The implications extend beyond immediate financial loss to include complete compromise of the token ecosystem's integrity and user trust. Users who hold tokens in this system face potential loss of their assets, while the entire token economy could be destabilized through artificial inflation or manipulation of supply. The vulnerability also demonstrates poor security practices in smart contract development, specifically the absence of comprehensive input validation and the failure to implement proper overflow protection mechanisms. Organizations should implement robust testing procedures including formal verification and static analysis to prevent such vulnerabilities in future deployments, as this type of flaw can lead to complete financial loss and system compromise. The vulnerability highlights the critical need for adherence to secure coding practices in blockchain development environments where financial assets are at stake.
This vulnerability represents a classic example of how insufficient attention to basic security principles can lead to catastrophic consequences in decentralized systems. The lack of overflow protection in the mintToken function creates an attack surface that allows for arbitrary balance manipulation, fundamentally undermining the security model of the token system. The implications for the broader Ethereum ecosystem include potential regulatory scrutiny and damage to trust in smart contract implementations, emphasizing the importance of rigorous security auditing and formal verification processes before deployment of critical financial smart contracts.