CVE-2018-13754 in CryptosisToken
Summary
by MITRE
The mintToken function of a smart contract implementation for CryptosisToken, 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 • 03/03/2020
The vulnerability identified as CVE-2018-13754 represents a critical integer overflow flaw within the mintToken function of the CryptosisToken smart contract deployed on the Ethereum blockchain. This vulnerability stems from inadequate input validation and arithmetic overflow handling within the contract's code implementation, creating a fundamental security weakness that directly impacts the token's integrity and user fund safety. The flaw allows the contract owner to manipulate user balances arbitrarily, effectively enabling unauthorized fund manipulation and potential theft of token holdings. The vulnerability manifests when the mintToken function processes token minting operations without proper bounds checking, permitting the owner to specify any arbitrary balance value for target users. This creates an environment where malicious actors with owner privileges can manipulate the token supply and user account balances beyond normal operational parameters.
The technical exploitation of this vulnerability occurs through direct function calls to the mintToken method with carefully crafted parameters that trigger the integer overflow condition. When the contract processes these inputs, the arithmetic operations exceed the maximum value that can be represented by the underlying data types, causing the system to wrap around to unexpected values. This overflow behavior allows the owner to set user balances to any desired amount, including potentially massive values that could destabilize the entire token ecosystem. The vulnerability directly maps to CWE-190, which identifies integer overflow and underflow conditions as critical weaknesses in software implementations. The specific nature of this flaw demonstrates how improper handling of arithmetic operations in smart contracts can lead to severe financial consequences and undermine the fundamental trust in blockchain-based token systems.
The operational impact of CVE-2018-13754 extends beyond immediate financial loss to encompass broader ecosystem damage and trust erosion. An attacker with owner privileges can manipulate token distributions, potentially creating artificial scarcity or flooding the market with excessive tokens. The vulnerability enables the creation of unlimited balances for specific users, which could be exploited to manipulate token prices, game the system, or cause denial of service conditions within token-based applications. Users who hold CryptosisToken may experience sudden and unexplained balance changes, leading to loss of confidence in the token's value and stability. The vulnerability also impacts smart contract interoperability, as other contracts relying on accurate token balances may fail or behave unexpectedly when encountering manipulated account states. This type of vulnerability falls under ATT&CK technique T1499.004, which covers network denial of service attacks through manipulation of token distributions and account states.
Mitigation strategies for this vulnerability require immediate contract hardening measures including comprehensive input validation, proper integer overflow detection, and implementation of safe arithmetic operations. The recommended approach involves adding explicit bounds checking before any arithmetic operations, implementing the SafeMath library or similar mathematical operation libraries that automatically detect and prevent overflow conditions. Contract owners should also implement proper access controls and audit trails to monitor any unusual mintToken function calls. Regular security audits and formal verification of smart contract code can help identify similar vulnerabilities before they can be exploited. Additionally, the contract should implement proper event logging for all minting operations to enable monitoring and detection of unauthorized balance manipulations. The vulnerability underscores the importance of following secure coding practices in blockchain development and highlights the need for comprehensive testing including edge case scenarios that could trigger integer overflow conditions. Organizations should also consider implementing multi-signature ownership controls and time locks for critical contract functions to reduce the risk of unauthorized exploitation.