Weight not properly refunded after EVM execution

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2022-39242: 0.76% estimated exploitation activity in the next 30 days; percentile 55.33 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Previously, the worst case weight was always accounted as the block weight for all cases. In case of large EVM gas refunds, this can lead to block spamming attacks -- the adversary can construct blocks with transactions that have large amount of refunds or unused gases with reverts, and as a result inflate up the chain gas prices. This issue is fixed by properly refund unused weights after each EVM execution. The impact of this issue is limited in that the spamming attack would still be costly for any adversary, and it has no ability to alter any chain state. Patches The issue is fixed in https://github.com/paritytech/frontier/pull/851 Workarounds None. References Are there any links users can visit to find out more? For more information If you have any questions or comments about this advisory: Open an issue in Frontier repo Email Wei

Published by the source

23 Sep 2022, 22:07 UTC

Last modified by the source

24 Oct 2024, 21:56 UTC

Source last checked

26 Oct 2026, 15:38 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-v57h-6hmh-g2p4

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# Patch Next advisory brief: CVE-2022-39242

Advisory: Weight not properly refunded after EVM execution
IDs: CVE-2022-39242, GHSA-v57h-6hmh-g2p4
Record: https://patchnext.com/advisories/cve-2022-39242 (revision 1, source checked 26 Oct 2026, 15:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io pallet-ethereum: affected <= 3.0.0

## Suggested inspection (read-only)
- crates.io pallet-ethereum: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on pallet-ethereum.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-v57h-6hmh-g2p4 (GitHub-reviewed advisory GHSA-v57h-6hmh-g2p4 lists affected ranges: crates.io pallet-ethereum >=0 <=3.0.0)

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