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ContractsApplication · Openzeppelin

CVE-2023-30542

HIGH · 8.8 CVSS v3.1 Published 2023-04-16
Fix available
A fix is available. Upgrade to 4.8.3 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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 queried through `getActions` appear to respect the original intended calldata. This issue has been patched in 4.8.3. As a workaround, ensure that all proposals that pass through governance have equal length `signatures` and `calldatas` parameters.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In OpenZeppelin Contracts' GovernorCompatibilityBravo module, the `propose` function does not validate that the `signatures` and `calldatas` arrays have equal length. When `signatures` is shorter, extra calldata elements are silently discarded during execution, causing actions to run with empty calldata despite appearing correct in events and query functions.

MitigationUpgrade to OpenZeppelin Contracts version 4.8.3 or later, or implement application-level validation to ensure `signatures` and `calldatas` arrays have equal length before submitting proposals.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ContractsApplication
Affected:>= 4.3.0, < 4.8.3
Contracts UpgradeableApplication
Affected:>= 4.3.0, < 4.8.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify OpenZeppelin Contracts version in use
    Check your package.json or node_modules/@openzeppelin/contracts/package.json for the installed version of @openzeppelin/contracts or @openzeppelin/contracts-upgradeable
    Affected if The installed version is >= 4.3.0 and < 4.8.3
  2. Locate GovernorCompatibilityBravo module
    Search your smart contract codebase for imports or deployments referencing GovernorCompatibilityBravo from OpenZeppelin
    Affected if GovernorCompatibilityBravo is imported or deployed in your governance contracts
  3. Identify proposals with mismatched arrays
    Query your governance contract for historical proposals and compare the length of the signatures and calldatas arrays for each proposal - any instance where signatures.length < calldatas.length indicates exploitation
    Affected if Any proposal exists where signatures and calldatas lengths differ
  4. Check if propose function is accessible
    Verify that the GovernorCompatibilityBravo proposal function can be called by any account that can create proposals in your governance system
    Affected if The propose function is callable without additional validation beyond standard proposal creation rights

You are affected if your environment uses OpenZeppelin Contracts or Contracts Upgradeable versions 4.3.0 through 4.8.2 with the GovernorCompatibilityBravo module and historical proposals show mismatched signatures/calldatas array lengths.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.8.3 or later
Fixed in 4.8.3
Interim mitigation

Upgrade to OpenZeppelin Contracts version 4.8.3 or later, or implement application-level validation to ensure `signatures` and `calldatas` arrays have equal length before submitting proposals.

Recommended fix High confidence

OpenZeppelin Contracts and Contracts Upgradeable version 4.8.3

  1. Upgrade OpenZeppelin Contracts to version 4.8.3 or later using your package manager (e.g., npm install @openzeppelin/[email protected] or pip install openzeppelin-contracts==4.8.3)
  2. Update the dependency lock file to reflect the new version
  3. Review and test all governance proposals that have been created with mismatched signatures and calldatas arrays to verify they now behave correctly
  4. If using Contracts Upgradeable, ensure you upgrade the upgradeable variant to the corresponding version (e.g., @openzeppelin/[email protected])
  5. Run your project's test suite, particularly any tests related to GovernorCompatibilityBravo, to confirm the fix works as expected
  6. Audit any governance proposals that passed with shorter signatures arrays to ensure no unintended actions were executed
Caveat Review OpenZeppelin 4.8.3 release notes for any breaking changes; minor version upgrades in the 4.x line typically have minimal breaking changes but always verify

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Contracts Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-30542 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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