CVE-2018-13566 in RETNToken
Summary
by MITRE
The mintToken function of a smart contract implementation for RETNToken, 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 • 02/27/2020
The vulnerability identified in CVE-2018-13566 represents a critical integer overflow flaw within the mintToken function of the RETNToken smart contract implementation on the Ethereum blockchain. This vulnerability stems from improper input validation and arithmetic operations that fail to account for the maximum limits of integer data types. The flaw allows an attacker with owner privileges to manipulate token balances by setting them to arbitrary values, effectively bypassing the normal token minting and distribution mechanisms. The vulnerability directly maps to CWE-191, which describes integer underflow and overflow conditions, and specifically manifests as an unchecked arithmetic operation that can result in unintended state modifications within the smart contract.
The technical execution of this vulnerability occurs when the owner invokes the mintToken function with malicious parameters that cause integer overflow during balance calculations. In Ethereum smart contracts, this typically involves manipulating the uint256 data type arithmetic operations where values exceed the maximum representable limit, causing the value to wrap around to zero or unexpected values. The vulnerability creates a path for privilege escalation where the contract owner can effectively mint unlimited tokens or manipulate existing user balances to arbitrary amounts. This flaw undermines the fundamental principles of token economics and blockchain security, as it allows for potential manipulation of token supply and user account balances without proper authorization mechanisms.
The operational impact of this vulnerability extends beyond simple balance manipulation to potentially compromise the entire token ecosystem. An attacker could exploit this flaw to create an unlimited supply of tokens, manipulate market dynamics, or gain unfair advantages in token-based systems such as governance voting rights or staking mechanisms. The vulnerability affects any system relying on the RETNToken contract where user balances are managed, potentially leading to financial losses for users and the broader token community. From an ATT&CK framework perspective, this vulnerability corresponds to privilege escalation techniques and resource hijacking, where an attacker leverages a legitimate function to manipulate system state. The impact is particularly severe in decentralized finance applications where token balances directly correlate to financial value and system integrity.
Mitigation strategies for this vulnerability require immediate code review and implementation of proper integer overflow protections. The smart contract should incorporate explicit bounds checking and validation before any arithmetic operations, utilizing libraries such as OpenZeppelin's SafeMath or similar overflow protection mechanisms. Additionally, access controls should be strengthened to limit mintToken function execution to only authorized entities, and comprehensive testing including fuzz testing should be implemented to identify similar vulnerabilities. The contract should also implement proper event logging and monitoring to detect unauthorized balance manipulations. Regular security audits and formal verification processes should be established to prevent similar issues in future smart contract deployments, ensuring that all arithmetic operations within the contract are protected against integer overflow conditions.