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Validity check missing in Frontier

Moderate severity GitHub Reviewed Published Oct 13, 2021 in polkadot-evm/frontier • Updated Feb 1, 2023

Package

cargo Frontier (Rust)

Affected versions

<= 0.1.0

Patched versions

None

Description

Impact

In the newly introduced signed Frontier-specific extrinsic for pallet-ethereum, a large part of transaction validation logic was only called in transaction pool validation, but not in block execution. Malicious validators can take advantage of this to put invalid transactions into a block.

The attack is limited in that the signature is always validated, and the majority of the validation is done again in the subsequent pallet-evm execution logic. However, do note that a chain ID replay attack was possible. In addition, spamming attacks are of main concerns, while they are limited by Substrate block size limits and other factors.

Patches

The issue is patched in commit 146bb48849e5393004be5c88beefe76fdf009aba.

References

Patch PR: polkadot-evm/frontier#495

For more information

If you have any questions or comments about this advisory:

Special thanks

Special thanks to @librelois, @nanocryk and the Moonbeam team for reporting and fixing this security vulnerability.

References

@sorpaas sorpaas published to polkadot-evm/frontier Oct 13, 2021
Published by the National Vulnerability Database Oct 13, 2021
Reviewed Oct 13, 2021
Published to the GitHub Advisory Database Oct 13, 2021
Last updated Feb 1, 2023

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
Low
Availability
None

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:L/A:N

EPSS score

0.152%
(52nd percentile)

Weaknesses

CVE ID

CVE-2021-41138

GHSA ID

GHSA-vj62-g63v-f8mf

Source code

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