CVE-2022-39242 is a medium-severity (CVSS 5.3) CWE-682 vulnerability in pallet-ethereum. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
Incorrect Calculation in Frontier leads to inflated Ethereum chain gas prices
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-39242.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
pallet-ethereumReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | pallet-ethereum | all versions | No fix |
Affected Products
frontierparityDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pallet-ethereum, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of pallet-ethereum for CVE-2022-39242. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
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.
Frequently Asked Questions
Is CVE-2022-39242 in your dependencies?
Find it across crates.io, including transitive dependencies.