CVE-2023-34234
Governor proposal creation may be blocked by frontrunning in OpenZeppelin
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 frontrunning protection. Users are advised to upgrade. Users unable to upgrade may submit the proposal creation transaction to an endpoint with frontrunning protection as a workaround.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Governor proposal creation may be blocked by frontrunning in OpenZeppelin
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 frontrunning protection. Users are advised to upgrade. Users unable to upgrade may submit the proposal creation transaction to an endpoint with frontrunning protection as a workaround.
- Record
CVE-2023-34234- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-862
- Updated
- 2026-11-02
EUVDEUVD-2023-1704
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 frontrunning protection. Users are advised to upgrade. Users unable to upgrade may submit the proposal creation transaction to an endpoint with frontrunning protection as a workaround.
- Record
EUVD-2023-1704- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-5h3x-9wvq-w4m2
OpenZeppelin Contracts's governor proposal creation may be blocked by frontrunning
Impact
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.
Patches
The problem has been patched in 4.9.1 by introducing opt-in frontrunning protection.
Workarounds
Submit the proposal creation transaction to an endpoint with frontrunning protection.
Credit
Reported by Lior Abadi and Joaquin Pereyra from Coinspect.
References
- Record
GHSA-5h3x-9wvq-w4m2- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-862
- Updated
- 2026-11-02
NVD
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 frontrunning protection. Users are advised to upgrade. Users unable to upgrade may submit the proposal creation transaction to an endpoint with frontrunning protection as a workaround.
- Record
CVE-2023-34234- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-862
- Updated
- 2026-11-02
OSV
Governor proposal creation may be blocked by frontrunning in OpenZeppelin
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 frontrunning protection. Users are advised to upgrade. Users unable to upgrade may submit the proposal creation transaction to an endpoint with frontrunning protection as a workaround.
- Record
CVE-2023-34234- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-862
- Updated
- 2026-11-02
OSVGHSA-5h3x-9wvq-w4m2
OpenZeppelin Contracts's governor proposal creation may be blocked by frontrunning
Impact
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.
Patches
The problem has been patched in 4.9.1 by introducing opt-in frontrunning protection.
Workarounds
Submit the proposal creation transaction to an endpoint with frontrunning protection.
Credit
Reported by Lior Abadi and Joaquin Pereyra from Coinspect.
References
- Record
GHSA-5h3x-9wvq-w4m2- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-862
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@openzeppelin/contractsnpm |
4.3.0 up to 4.9.1 | 4.9.1 |
@openzeppelin/contracts-upgradeablenpm |
4.3.0 up to 4.9.1 | 4.9.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-34234 is a medium vulnerability (CVSS 5.3) in Openzeppelin Contracts, published June 7, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.60%, the 48th percentile. Fixed in @openzeppelin/contracts 4.9.1.
References
github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-5h3x-9wvq-w4m2
nvd.nist.gov/vuln/detail/CVE-2023-34234