CVE-2023-34234Network attack vector

Proposal denial via proposer-independent identifiers

Published Jun 7, 2023 · Updated Feb 6, 2025

Denial of service in OpenZeppelin Contracts 4.3.0 through 4.9.0 allows remote attackers to block governance proposals via frontrunning. The proposal identifier does not bind the proposer, so an observer can copy a pending proposal, submit it first, become its recorded proposer, and then cancel it. Any network participant able to observe pending transactions can repeat the sequence, interrupting governance proposal creation without prior privileges.

CVSS severity5.3
Medium
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in OpenZeppelin Contracts 4.3.0 through 4.9.0 allows remote attackers to block governance proposals via frontrunning. The proposal identifier does not bind the proposer, so an observer can copy a pending proposal, submit it first, become its recorded proposer, and then cancel it. Any network participant able to observe pending transactions can repeat the sequence, interrupting governance proposal creation without prior privileges.

The record

CVE
CVE-2023-34234
Published
Jun 7, 2023
Updated
Feb 6, 2025
Vendor
OpenZeppelin
Product
OpenZeppelin Contracts
Classifications
CWE-862, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 7, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 6, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>=4.3.0, < 4.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenZeppelin · OpenZeppelin Contractsversion=>=4.3.0, < 4.9.1

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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