CVE-2023-30542
MEDIUMCVE-2023-30542 is a medium-severity (CVSS 6.8) Improper Input Validation vulnerability in @openzeppelin/contracts. O3 Security confirms whether CVE-2023-30542 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
GovernorCompatibilityBravo may trim proposal calldata
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
@openzeppelin/contractsnpm@openzeppelin/contracts-upgradeablenpmDescription
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @openzeppelin/contracts | ≥ 4.3.0&&< 4.8.3 | 4.8.3 |
| 📦npm | @openzeppelin/contracts-upgradeable | ≥ 4.3.0&&< 4.8.3 | 4.8.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @openzeppelin/contracts. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @openzeppelin/contracts to 4.8.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-30542 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2023-30542 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2023-30542. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-30542 in your dependencies?
O3 detects CVE-2023-30542 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.