CVE-2018-13551 in Bgamecoin
Summary
by MITRE
The mintToken function of a smart contract implementation for Bgamecoin, 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-2018-13551 represents a critical integer overflow flaw within the mintToken function of the Bgamecoin Ethereum smart contract implementation. This vulnerability stems from inadequate input validation and arithmetic handling within the smart contract code, specifically affecting the token's issuance mechanism. The flaw allows an attacker with owner privileges to manipulate token balances by exploiting the overflow condition, potentially enabling unauthorized minting of tokens or manipulation of user account balances.
The technical root cause of this vulnerability aligns with CWE-190, which categorizes integer overflow conditions that occur when an arithmetic operation produces a result that exceeds the maximum value representable by the target data type. In Ethereum smart contracts, this typically manifests when unsigned integer variables exceed their maximum bounds during arithmetic operations, causing the value to wrap around to zero or negative values. The mintToken function likely performs arithmetic operations without proper overflow checks, creating a scenario where malicious input can trigger unexpected behavior in the contract's balance management system.
This vulnerability presents significant operational impact within the Bgamecoin ecosystem, as it allows the contract owner to arbitrarily manipulate user balances without proper authorization. The implications extend beyond simple balance manipulation to potentially enable theft of tokens, creation of unlimited supply, or disruption of the token's economic model. An attacker could exploit this vulnerability to increase their own token holdings while simultaneously reducing other users' balances, effectively creating a form of unauthorized token redistribution that undermines the integrity of the token economy.
The security implications of this vulnerability extend to the broader Ethereum smart contract security landscape, as it demonstrates the critical importance of implementing proper integer overflow protections in all arithmetic operations within smart contracts. From an attack perspective, this vulnerability aligns with ATT&CK technique T1548.001, which involves privilege escalation through manipulation of system or application-level components. The vulnerability also intersects with T1499.004, as it could enable unauthorized modification of asset values within the system, potentially leading to financial loss for token holders.
Mitigation strategies for this vulnerability require immediate implementation of proper overflow checks within the mintToken function and all arithmetic operations within the smart contract. The recommended approach includes implementing bounds checking mechanisms, using safe math libraries such as OpenZeppelin's SafeMath, and ensuring that all integer operations include validation to prevent overflow conditions. Additionally, the contract should undergo comprehensive security auditing to identify and remediate similar vulnerabilities throughout the codebase. Regular code reviews and formal verification processes should be implemented to prevent similar issues in future smart contract deployments. The contract owner should also consider implementing access controls and multi-signature requirements for critical functions to reduce the attack surface and prevent unauthorized exploitation of privileged functions.