CVE-2022-21685

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.

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.

### Impact 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. It is recommended that you apply the patch as soon as possible. If you do not use MODEXP precompile in your runtime, then you are not impacted. ### Patches Patches are applied in PR #549. ### Workarounds None. ### References Patch PR: #549 ### Credits Thanks to SR-Labs for discovering the security vulnerability, and thanks to PureStake team for the patches. ### For more information If you have any questions or comments about this advisory: * Open an issue in the [Frontier repo](https://github.com/paritytech/frontier)

### Impact 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. It is recommended that you apply the patch as soon as possible. If you do not use MODEXP precompile in your runtime, then you are not impacted. ### Patches Patches are applied in PR #549. ### Workarounds None. ### References Patch PR: #549 ### Credits Thanks to SR-Labs for discovering the security vulnerability, and thanks to PureStake team for the patches. ### For more information If you have any questions or comments about this advisory: * Open an issue in the [Frontier repo](https://github.com/paritytech/frontier)

Frontier es la capa de compatibilidad con Ethereum de Substrate. Antes del número de commit "8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664", un error en la implementación de precompilación MODEXP de Frontier puede causar un desbordamiento de enteros en determinadas condiciones. Esto causará un bloqueo del nodo en las versiones de depuración. Para las compilaciones de lanzamiento (y los binarios WebAssembly de producción), el impacto es limitado, ya que sólo puede causar un desbordamiento normal de EVM. Los usuarios que no usan la precompilación MODEXP en su tiempo de ejecución no están afectados. Un parche está disponible en el pull request #549