CVE-2018-13501 in HRWtoken
Summary
by MITRE
The mintToken function of a smart contract implementation for HRWtoken, 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-2018-13501 represents a critical integer overflow flaw within the mintToken function of the HRWtoken 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 the contract owner to manipulate token balances by exploiting the overflow behavior, effectively enabling arbitrary balance manipulation for any user account within the token ecosystem.
The technical implementation of this vulnerability manifests through the mintToken function's failure to properly validate or constrain integer values during token creation or minting operations. When the contract attempts to increment token balances or perform arithmetic operations on integer variables, the overflow occurs because the system does not implement proper bounds checking or overflow detection mechanisms. This vulnerability directly maps to CWE-190, which identifies integer overflow conditions, and specifically relates to CWE-682, which covers incorrect arithmetic operations. The root cause lies in the absence of proper overflow protection mechanisms within the smart contract's core logic.
From an operational perspective, this vulnerability presents a severe security risk to the HRWtoken ecosystem and its users. The contract owner can exploit this flaw to artificially inflate or reduce any user's token balance to arbitrary values, potentially leading to unauthorized token distribution, manipulation of tokenomics, or even complete theft of user assets. The impact extends beyond individual user accounts as it undermines the fundamental trust and integrity of the token's supply mechanism, potentially affecting market stability and user confidence in the entire token implementation. This vulnerability also aligns with ATT&CK technique T1059.001, which covers command and control through code injection, as the overflow can be leveraged to execute unintended contract operations.
Mitigation strategies for this vulnerability require immediate implementation of comprehensive input validation and integer overflow protection mechanisms. Smart contract developers must incorporate explicit bounds checking for all integer operations, utilize safe math libraries that automatically detect and prevent overflow conditions, and implement proper access controls for privileged functions. The contract owner should consider implementing reentrancy guards, using established secure coding practices, and conducting thorough security audits before deploying any token contracts to production environments. Additionally, developers should leverage formal verification tools and automated testing frameworks to identify similar vulnerabilities in smart contract implementations, as this class of vulnerability is particularly dangerous in decentralized applications where the code is immutable and publicly accessible.