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Weight not properly refunded after EVM execution

Moderate severity GitHub Reviewed Published Sep 23, 2022 in polkadot-evm/frontier • Updated Oct 24, 2024

Package

cargo pallet-ethereum (Rust)

Affected versions

<= 3.0.0

Patched versions

None

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 polkadot-evm/frontier#851

Workarounds

None.

References

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For more information

If you have any questions or comments about this advisory:

References

@sorpaas sorpaas published to polkadot-evm/frontier Sep 23, 2022
Published to the GitHub Advisory Database Sep 23, 2022
Reviewed Sep 23, 2022
Published by the National Vulnerability Database Sep 24, 2022
Last updated Oct 24, 2024

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS score

0.091%
(40th percentile)

Weaknesses

CVE ID

CVE-2022-39242

GHSA ID

GHSA-v57h-6hmh-g2p4

Source code

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