CVE-2021-41138Network attack vector

Invalid block inclusion via omitted execution validation

Published Oct 13, 2021 · Updated Aug 4, 2024

Improper input validation in Frontier before commit 146bb48 allows attackers controlling validators to include invalid transactions in blocks. The pallet-ethereum signed-extrinsic path performed transaction checks during pool validation but omitted them during block execution. Control of a validator is required; signatures remain checked, while the gap permits chain-ID replay and bounded transaction spam.

CVSS severity5.3
Medium
EPSS probability1.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Frontier before commit 146bb48 allows attackers controlling validators to include invalid transactions in blocks. The pallet-ethereum signed-extrinsic path performed transaction checks during pool validation but omitted them during block execution. Control of a validator is required; signatures remain checked, while the gap permits chain-ID replay and bounded transaction spam.

The record

CVE
CVE-2021-41138
Published
Oct 13, 2021
Updated
Aug 4, 2024
Vendor
Parity Technologies
Product
Frontier
Classifications
CWE-20, T1565.001
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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=< 146bb48

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

Parity Technologies · Frontierversion=< 146bb48

Published CVSS scores

5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
5.0NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

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.

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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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1565.001Stored Data Manipulation

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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