CVE-2022-21685: Parity Frontier

Medium severity, CVSS 6.5. EPSS: 1.3% chance of exploitation in the next 30 days.

Frontier is Substrate's Ethereum compatibility layer. Prior to commit number `8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664`, a bug in Frontier's MODEXP precompile implementation can cause an integer underflow in certain conditions. This will cause a node crash for debug builds. For release builds (and production WebAssembly binaries), the impact is limited as it can only cause a normal EVM out-of-gas. Users who do not use MODEXP precompile in their runtime are not impacted. A patch is available in pull request #549.

Affected products

• Parity Frontier: up to and including 2022-01-13

Published 2022-01-14. Last modified 2026-06-17.