CVE-2018-13223 in R Time Token v3
Summary
by MITRE
The sell function of a smart contract implementation for R Time Token v3 (RS) (Contract Name: RTokenMain), an Ethereum token, has an integer overflow in which "amount * sellPrice" can be zero, consequently reducing a seller's assets.
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Analysis
by VulDB Data Team • 02/25/2020
The vulnerability identified in CVE-2018-13223 represents a critical integer overflow flaw within the R Time Token v3 smart contract implementation on the Ethereum blockchain. This vulnerability specifically affects the sell function of the RTokenMain contract, which is designed to facilitate token transactions and asset management for R Time Token holders. The flaw stems from improper input validation and arithmetic operations that fail to account for potential overflow conditions in the underlying blockchain smart contract code.
The technical implementation of this vulnerability occurs when the sell function processes token redemption requests where the multiplication operation "amount * sellPrice" results in an integer overflow condition. When this arithmetic operation exceeds the maximum value that can be represented within the allocated integer data type, the result wraps around to zero or another unexpected value. This overflow condition directly impacts the calculation of asset redemption amounts, effectively allowing malicious actors to manipulate the token redemption process and reduce the actual assets that should be credited to sellers. The vulnerability falls under the CWE-190 category of integer overflow/underflow, which is a well-documented weakness in software development that particularly affects blockchain smart contracts due to their deterministic nature and immutable execution environment.
The operational impact of this vulnerability extends beyond simple financial loss, as it fundamentally undermines the integrity and trustworthiness of the token redemption mechanism. When sellers attempt to redeem their R Time Tokens, they may receive zero or significantly reduced asset values due to the overflow condition, creating a potential for substantial financial losses across the token ecosystem. This flaw directly affects the contract's ability to accurately process transactions and maintain proper accounting of token holdings, potentially leading to broader issues within the token's economic model and user confidence. The vulnerability also creates opportunities for exploitation through automated attack vectors, as the overflow condition can be consistently triggered with specific input values, making it a prime target for malicious actors seeking to manipulate token economics.
From a cybersecurity perspective, this vulnerability demonstrates the critical importance of proper input validation and arithmetic boundary checking in blockchain smart contract development. The flaw aligns with ATT&CK technique T1210 which involves exploiting weaknesses in systems to gain access to sensitive information or manipulate system behavior. The vulnerability's impact is particularly severe because it operates at the core financial transaction level of the smart contract, making it difficult to detect through standard code review processes and potentially allowing for cascading effects throughout the token's economic ecosystem. Organizations implementing blockchain solutions must prioritize rigorous testing of arithmetic operations, including overflow and underflow conditions, and implement proper boundary checks to prevent similar vulnerabilities from compromising their smart contract systems.
Mitigation strategies for this vulnerability should include immediate code review and patching of the affected smart contract implementation to ensure proper integer overflow protection mechanisms are in place. Developers should implement explicit checks for arithmetic operations, utilize safe math libraries, and conduct comprehensive testing including boundary condition testing to prevent similar issues in future deployments. The vulnerability also underscores the need for formal verification processes and third-party security audits for critical smart contract implementations, particularly those handling significant financial transactions or asset management functions. Organizations should also consider implementing monitoring systems to detect anomalous transaction patterns that might indicate exploitation attempts.