CVE-2018-13676 in Orderbook Presale Token
Summary
by MITRE
The mintToken function of a smart contract implementation for Orderbook Presale Token (OBP), 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 CVE-2018-13676 vulnerability resides within the Orderbook Presale Token (OBP) smart contract implementation on the Ethereum blockchain, representing a critical integer overflow flaw that fundamentally compromises the contract's integrity and token distribution mechanisms. This vulnerability specifically targets the mintToken function, which serves as the primary mechanism for creating new tokens within the contract. The flaw arises from insufficient input validation and overflow checking during arithmetic operations, allowing an attacker with owner privileges to manipulate token balances in ways that were never intended by the contract's design. The vulnerability's classification as an integer overflow aligns with CWE-190, which specifically addresses issues related to integer overflow and unsigned integer overflow conditions that can lead to unexpected behavior in software systems. When exploited, this vulnerability enables the contract owner to arbitrarily set any user's token balance to any desired value, effectively bypassing the normal token distribution and accounting mechanisms that should govern the contract's operation.
The operational impact of this vulnerability extends far beyond simple financial manipulation, as it fundamentally undermines the trust model that governs blockchain-based token systems and creates potential for significant financial loss and contract compromise. An attacker with owner access can increase their own token holdings beyond the intended limits, manipulate token distributions to favor specific parties, or even create artificial scarcity by reducing other users' balances to zero. This type of vulnerability directly impacts the core principles of blockchain security including transparency, immutability, and fair distribution, as it allows for unauthorized manipulation of the token supply and user balances. The vulnerability's exploitation does not require complex attack vectors or external dependencies, making it particularly dangerous as it can be executed by anyone with owner privileges, potentially leading to immediate financial gain or contract manipulation that could affect all token holders. The implications of such a flaw extend to the broader Ethereum ecosystem, as it demonstrates how seemingly minor implementation errors can create significant security risks in decentralized applications.
The mitigation strategies for CVE-2018-13676 require immediate remediation of the underlying smart contract code through comprehensive input validation and overflow checking mechanisms. Smart contract developers must implement proper bounds checking and use secure arithmetic operations that prevent integer overflow conditions, typically by utilizing libraries or frameworks that provide built-in overflow protection such as OpenZeppelin's SafeMath library. The vulnerability's exploitation highlights the importance of thorough code auditing and formal verification processes for smart contracts, as this type of issue could have been prevented through proper security testing and adherence to established best practices. Organizations should also implement robust access control mechanisms and consider multi-signature wallets for contract ownership to reduce the risk of unauthorized exploitation. Additionally, the incident underscores the necessity of following industry standards such as those outlined in the OWASP Smart Contract Security Verification Standard, which provides comprehensive guidance for identifying and preventing common smart contract vulnerabilities. The vulnerability's classification under ATT&CK framework for blockchain environments would likely fall under the privilege escalation category, as it allows an attacker to gain unauthorized control over token balances and contract state, potentially leading to further exploitation opportunities within the broader contract ecosystem.