Impact The Base64.encode function encodes a bytes input by iterating over it in chunks of 3 bytes. When this input is not a multiple of 3, the last iteration may read parts of the memory that are beyond the input buffer. Although the encode function pads the output for these cases, up to 4 bits of data are kept between the encoding and padding, corrupting the output if these bits …
OpenZeppelin Contracts is a library for smart contract development. A merge issue when porting the 5.0.1 patch to the 4.9 branch caused a line duplication. In the version of Multicall.sol released in @openzeppelin/contracts@4.9.4 and @openzeppelin/contracts-upgradeable@4.9.4, all subcalls are executed twice. Concretely, this exposes a user to unintentionally duplicate operations like asset transfers. The duplicated delegatecall was removed in version 4.9.5. The 4.9.4 version is marked as deprecated. Users are advised …
OpenZeppelin Contracts is a library for secure smart contract development. Starting in version 4.0.0 and prior to version 4.9.3, contracts using ERC2771Context along with a custom trusted forwarder may see _msgSender return address(0) in calls that originate from the forwarder with calldata shorter than 20 bytes. This combination of circumstances does not appear to be common, in particular it is not the case for MinimalForwarder from OpenZeppelin Contracts, or any …
OpenZeppelin Contracts is a library for smart contract development. Starting in version 4.7.0 and prior to version 4.9.2, when the verifyMultiProof, verifyMultiProofCalldata, procesprocessMultiProof, or processMultiProofCalldat functions are in use, it is possible to construct merkle trees that allow forging a valid multiproof for an arbitrary set of leaves. A contract may be vulnerable if it uses multiproofs for verification and the merkle tree that is processed includes a node with …
OpenZeppelin Contracts is a library for smart contract development. By frontrunning the creation of a proposal, an attacker can become the proposer and gain the ability to cancel it. The attacker can do this repeatedly to try to prevent a proposal from being proposed at all. This impacts the Governor contract in v4.9.0 only, and the GovernorCompatibilityBravo contract since v4.3.0. This problem has been patched in 4.9.1 by introducing opt-in …
OpenZeppelin Contracts is a library for secure smart contract development. The proposal creation entrypoint (propose) in GovernorCompatibilityBravo allows the creation of proposals with a signatures array shorter than the calldatas array. This causes the additional elements of the latter to be ignored, and if the proposal succeeds the corresponding actions would eventually execute without any calldata. The ProposalCreated event correctly represents what will eventually execute, but the proposal parameters as …
OpenZeppelin Contracts is a library for secure smart contract development. A function in the implementation contract may be inaccessible if its selector clashes with one of the proxy's own selectors. Specifically, if the clashing function has a different signature with incompatible ABI encoding, the proxy could revert while attempting to decode the arguments from calldata. The probability of an accidental clash is negligible, but one could be caused deliberately and …
OpenZeppelin Contracts is a library for secure smart contract development. The ERC721Consecutive contract designed for minting NFTs in batches does not update balances when a batch has size 1 and consists of a single token. Subsequent transfers from the receiver of that token may overflow the balance as reported by balanceOf. The issue exclusively presents with batches of size 1. The issue has been patched in 4.8.2.
OpenZeppelin Contracts is a library for secure smart contract development. This issue concerns instances of Governor that use the module GovernorVotesQuorumFraction, a mechanism that determines quorum requirements as a percentage of the voting token's total supply. In affected instances, when a proposal is passed to lower the quorum requirements, past proposals may become executable if they had been defeated only due to lack of quorum, and the number of votes …
OpenZeppelin Contracts is a library for secure smart contract development. The functions ECDSA.recover and ECDSA.tryRecover is vulnerable to a kind of signature malleability due to accepting EIP-2098 compact signatures in addition to the traditional 65 byte signature format. This is only an issue for the functions that take a single bytes argument, and not the functions that take r, v, s or r, vs as separate arguments. The potentially affected …
OpenZeppelin Contracts is a library for secure smart contract development. The target contract of an EIP-165 supportsInterface query can cause unbounded gas consumption by returning a lot of data, while it is generally assumed that this operation has a bounded cost. The issue has been fixed in v4.7.2. Users are advised to upgrade. There are no known workarounds for this issue.
OpenZeppelin Contracts is a library for secure smart contract development. Contracts using the cross chain utilities for Arbitrum L2, CrossChainEnabledArbitrumL2 or LibArbitrumL2, will classify direct interactions of externally owned accounts (EOAs) as cross chain calls, even though they are not started on L1. This issue has been patched in v4.7.2. Users are advised to upgrade. There are no known workarounds for this issue.
OpenZeppelin Contracts is a library for smart contract development. Versions 4.1.0 until 4.7.1 is vulnerable to the SignatureChecker reverting. SignatureChecker.isValidSignatureNow is not expected to revert. However, an incorrect assumption about Solidity 0.8's abi.decode allows some cases to revert, given a target contract that does not implement EIP-1271 as expected. The contracts that may be affected are those that use SignatureChecker to check the validity of a signature and handle invalid …
OpenZeppelin Contracts is a library for smart contract development. Versions 4.0.0 until 4.7.1 is vulnerable to ERC165Checker reverting instead of returning false. ERC165Checker.supportsInterface is designed to always successfully return a boolean, and under no circumstance revert. However, an incorrect assumption about Solidity 0.8's abi.decode allows some cases to revert, given a target contract that does not implement EIP-165 as expected, specifically if it returns a value other than 0 or …
The storage layout of the ERC2771ContextUpgradeable is not constant
In OpenZeppelin <=v4.4.0, initializer functions that are invoked separate from contract creation (the most prominent example being minimal proxies) may be reentered if they make an untrusted non-view external call. Once an initializer has finished running it can never be re-executed. However, an exception put in place to support multiple inheritance made reentrancy possible, breaking the expectation that there is a single execution.
Improper Neutralization in @openzeppelin/contracts-upgradeable.
Initializer functions that are invoked separate from contract creation (the most prominent example being minimal proxies) may be reentered if they make an untrusted non-view external call. Once an initializer has finished running it can never be re-executed.
When ERC1155 tokens are minted, a callback is invoked on the receiver of those tokens, as required by the spec. When including the ERC1155Supply extension, total supply is not updated until after the callback, thus during the callback the reported total supply is lower than the real number of tokens in circulation. Impact If a system relies on accurately reported supply, an attacker may be able to mint tokens and …
Upgradeable contracts using UUPSUpgradeable may be vulnerable to an attack affecting uninitialized implementation contracts. We will update this advisory with more information soon.
OpenZeppelin Contracts is a library for smart contract development. In affected versions upgradeable contracts using UUPSUpgradeable may be vulnerable to an attack affecting uninitialized implementation contracts. A fix is included in version 4.3.2 of @openzeppelin/contracts and @openzeppelin/contracts-upgradeable. For users unable to upgrade; initialize implementation contracts using UUPSUpgradeable by invoking the initializer function (usually called initialize). An example is provided in the forum.
OpenZepplin is a library for smart contract development.Further details about the vulnerability will be disclosed at a later date. As a workaround revoke the executor role from accounts not strictly under the team's control. We recommend revoking all executors that are not also proposers. When applying this mitigation, ensure there is at least one proposer and executor remaining.