CVE intelligence and bounded remediation

CVE-2021-39193 — Frontier is Substrate's Ethereum compatibility layer

Medium CVSS 5.3

Frontier is Substrate's Ethereum compatibility layer. Prior to commit number 0b962f218f0cdd796dadfe26c3f09e68f7861b26, a bug in `pallet-ethereum` can cause invalid transactions to be included in the Ethereum block state in `pallet-ethereum` due to not validating the input data size. Any invalid transactions included this way have no possibility to alter the internal Ethereum or Substrate state. The transaction will appear to have be included, but is of no effect as it is rejected by the EVM engine. The impact is further limited by Substrate extrinsic size constraints. A patch is available in commit number 0b962f218f0cdd796dadfe26c3f09e68f7861b26. There are no workarounds aside from applying the patch.

Severity
Medium
CVSS
5.3 (3.1)
Published
2021-09-03
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-20, CWE-1284

Affected products

  • parity / frontier

Matched remediation archetype

General vulnerability remediation

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Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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