CVE-2018-13567 in SDR
Summary
by MITRE
The mintToken function of a smart contract implementation for SDR, 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 as CVE-2018-13567 represents a critical integer overflow flaw within the mintToken function of an Ethereum-based smart contract implementing the SDR token. This vulnerability resides in the fundamental arithmetic operations of the smart contract code, where insufficient input validation and overflow checking mechanisms permit malicious exploitation by the contract owner. The flaw specifically manifests when the mintToken function processes token minting operations without proper bounds checking, creating a scenario where arithmetic operations can exceed the maximum value that can be represented by the underlying data type.
The technical implementation of this vulnerability stems from the absence of proper overflow detection mechanisms within the smart contract's arithmetic operations. When the contract owner invokes the mintToken function, the system fails to validate whether the resulting token balance would exceed the maximum value permitted by the integer data type being used. This allows an attacker with owner privileges to manipulate the token supply by setting arbitrary user balances to any desired value, effectively bypassing normal token distribution mechanisms and potentially enabling unlimited token creation.
The operational impact of this vulnerability extends beyond simple financial manipulation as it fundamentally compromises the integrity and security of the entire token ecosystem. An attacker with owner access can manipulate user balances to create artificial wealth distribution, potentially enabling fraudulent activities such as creating unlimited tokens, manipulating market prices, or executing arbitrary balance manipulations that could destabilize the token's economic model. This vulnerability directly violates the core principles of blockchain security and trustless systems, as it allows privileged users to subvert the normal consensus mechanisms and token economics.
The vulnerability aligns with CWE-190, Integer Overflow or Wraparound, which specifically addresses issues where integer arithmetic operations produce results that exceed the maximum value representable by the data type. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and resource hijacking, as the contract owner can leverage this flaw to gain unauthorized control over token distributions and user balances. The exploitability of this vulnerability is high given that it requires only owner privileges and involves straightforward manipulation of arithmetic operations within the smart contract's mintToken function.
Mitigation strategies for this vulnerability require immediate implementation of comprehensive input validation and overflow protection mechanisms within the smart contract code. Developers should implement explicit bounds checking before any arithmetic operations, utilize safe math libraries that automatically detect and prevent overflow conditions, and ensure that all token minting operations include proper validation of input parameters. Additionally, the contract owner should implement proper access control mechanisms and conduct thorough security audits to identify similar vulnerabilities in other arithmetic operations. Regular code reviews and formal verification processes should be established to prevent recurrence of such issues in future smart contract implementations, ensuring that all mathematical operations within blockchain applications maintain integrity and prevent unauthorized manipulation of token balances and supply.