Is This vulnerability exploited in the wild?

No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

How severe is This vulnerability?

Informational severity, published 14 March 2022.

Which products and versions are affected?

@openzeppelin/contracts-upgradeable (npm) SEMVER:introduced=4.0.0,fixed=4.3.0; OpenZeppelin Contracts Upgradeable >=4.0.0, <4.3.0.

Is there a fix for This vulnerability?

Yes. @openzeppelin/contracts-upgradeable (npm): upgrade to 4.3.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Check whether you run @openzeppelin/contracts-upgradeable (npm) or OpenZeppelin Contracts Upgradeable at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

OpenZeppelin Contracts Upgradeable inconsistent storage layout in ERC2771ContextUpgradeable

Q: Is there a fix for This vulnerability?

Yes. @openzeppelin/contracts-upgradeable (npm): upgrade to 4.3.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: Am I affected?

Check whether you run @openzeppelin/contracts-upgradeable (npm) or OpenZeppelin Contracts Upgradeable at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Severity: info · Published 2022-03-14

OpenZeppelin Contracts Upgradeable is a library providing secure, upgradeable smart contracts for Ethereum and other blockchains. A change in the storage layout of the ERC2771ContextUpgradeable contract between versions 4.0–4.2 (51 slots) and 4.3+ (50 slots) can cause smart contract upgrades to fail or behave unexpectedly if developers upgrade without accounting for the layout difference. Projects using this library must carefully plan upgrades to avoid breaking their deployed contracts.

Technologies: @openzeppelin/contracts-upgradeable (npm), OpenZeppelin Contracts Upgradeable. Vendors: npm, OpenZeppelin.

Quick answers

Is This vulnerability exploited in the wild?: No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?: Informational severity, published 14 March 2022.
Which products and versions are affected?: @openzeppelin/contracts-upgradeable (npm) SEMVER:introduced=4.0.0,fixed=4.3.0; OpenZeppelin Contracts Upgradeable >=4.0.0, <4.3.0.
Is there a fix for This vulnerability?: Yes. @openzeppelin/contracts-upgradeable (npm): upgrade to 4.3.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is This vulnerability attacked?: It is in a software library.
Am I affected?: Check whether you run @openzeppelin/contracts-upgradeable (npm) or OpenZeppelin Contracts Upgradeable at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

@openzeppelin/contracts-upgradeable (npm): upgrade to 4.3.0 or later
```
npm install @openzeppelin/contracts-upgradeable@4.3.0
```

Technical details

The ERC2771ContextUpgradeable contract in OpenZeppelin Contracts Upgradeable versions 4.0.0, 4.1.0, and 4.2.0 uses 51 storage slots, while version 4.3.0 and later use 50 slots. This change in storage layout is incompatible with upgradeable contract patterns used in Ethereum smart contracts, which rely on consistent storage structure to safely upgrade implementations. When an existing deployed proxy contract using version <4.3.0 is upgraded to >=4.3.0, the differing storage layout can cause data corruption or unexpected behavior. The vulnerability affects any project that upgrades ERC2771ContextUpgradeable without accounting for the layout change. OpenZeppelin recommends using their Upgrades Plugins for Hardhat and Truffle to detect such issues, or manually copying the older implementation as a workaround.

Affected products

OpenZeppelin Contracts Upgradeable >=4.0.0, <4.3.0

Timeline

2022-03-14: disclosed
2022-03-14: patched: Fixed in version 4.3.0

References

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