CVE-2018-13703 in CERB_Coin
Summary
by MITRE
The mintToken function of a smart contract implementation for CERB_Coin, 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 vulnerability identified as CVE-2018-13703 represents a critical integer overflow flaw within the mintToken function of the CERB_Coin Ethereum token smart contract implementation. This vulnerability stems from improper input validation and arithmetic operation handling within the smart contract code, creating a scenario where the contract owner can manipulate user balances arbitrarily. The flaw occurs during the token minting process when the contract fails to properly validate or constrain the numerical values being processed, allowing for overflow conditions that can result in unintended balance modifications.
The technical execution of this vulnerability involves the contract owner leveraging the integer overflow condition to manipulate the balance of any user account within the token ecosystem. When the mintToken function processes token creation requests, it does not adequately check for overflow conditions in the arithmetic operations that determine new user balances. This allows an attacker with owner privileges to input values that cause the balance calculation to wrap around to unexpected values, potentially setting user balances to extremely large or negative numbers. The vulnerability specifically relates to CWE-190, which addresses integer overflow and underflow conditions in software implementations.
From an operational impact perspective, this vulnerability compromises the fundamental integrity of the token economy by enabling the contract owner to manipulate user balances without detection. The implications extend beyond simple balance manipulation to potentially undermine trust in the token system and create opportunities for financial loss or exploitation. Attackers could theoretically set user balances to zero, causing users to lose access to their tokens, or manipulate balances to create artificial scarcity or abundance within the token ecosystem. This vulnerability essentially grants the contract owner unlimited control over the token distribution and user account balances, creating a dangerous centralization of power within the decentralized system.
The mitigation strategies for this vulnerability require immediate code-level fixes that implement proper input validation and arithmetic boundary checks within the smart contract. Developers must ensure that all integer operations in the mintToken function include overflow detection mechanisms, typically through the use of require statements that validate input ranges before processing. The implementation should utilize safe arithmetic libraries or built-in overflow protection features available in modern Ethereum development frameworks. Additionally, the contract should implement proper access controls and audit logging to detect unauthorized balance manipulations. This vulnerability aligns with ATT&CK technique T1548.001, which covers privilege escalation through code injection or manipulation of system-level functions, highlighting the need for robust contract access controls and regular security auditing. Organizations should conduct comprehensive security reviews of all smart contract implementations and implement continuous monitoring to detect anomalous balance changes that might indicate exploitation of similar vulnerabilities.