OpenZeppelin Confidential Contracts is an experimental library for developing applications on the Zama fhEVM. Prior to 0.3.1, the ERC7984 contract tracked confidential total supply with an euint64 value, and an overflowing internal _mint operation could fail silently. The wrap and onTransferReceived functions in contracts/token/ERC7984/extensions/ERC7984ERC20Wrapper.sol did not handle that failure, so a user could transfer the underlying token without receiving the corresponding confidential wrapped token.
With the default rate(), the wrapper fills after approximately 18.4 trillion tokens, and subsequent wrapping requests can cause loss of funds. This issue is fixed in version 0.3.1.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/commit/c620…
security-advisories@github.com
https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/pull/271
security-advisories@github.com
https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/releases/ta…
security-advisories@github.com
https://github.com/OpenZeppelin/openzeppelin-confidential-contracts/security/ad…
security-advisories@github.com