CVE-2021-41138: parity frontier Improper Input Validation

Vulnerability summary

CVE-2021-41138 is a medium (CVSS 5.3) Improper Input Validation vulnerability in parity frontier. EPSS estimates a 1.38% chance of exploitation in the next 30 days, higher than 71.9% of scored vulnerabilities.

Timeline

1. 13-10-2021
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

Frontier is Substrate's Ethereum compatibility layer. 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. The issue is patched in commit `146bb48849e5393004be5c88beefe76fdf009aba`.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.