{"id":"CVE-2022-21685","aliases":["EUVD-2022-0562","GHSA-cjg2-2fjg-fph4"],"status":"published","title":"Integer underflow in Frontier","description":"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.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01375,"percentile":0.72255,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-191"],"published":"2022-01-14T17:05:11Z","modified":"2026-10-28T02:30:34Z","affected":[{"source":"ghsa","ecosystem":"crates.io","package":"pallet-evm-precompile-modexp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.0.0"}]}]},{"source":"osv","ecosystem":"crates.io","package":"pallet-evm-precompile-modexp","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"last_affected":"1.0.0"}]}]}],"products":[{"vendor":"parity","product":"frontier"},{"vendor":"paritytech","product":"frontier"},{"vendor":"polkadot-evm","product":"frontier"}],"references":[{"url":"https://github.com/paritytech/frontier/security/advisories/GHSA-cjg2-2fjg-fph4","tags":["x_refsource_CONFIRM","x_transferred","Patch","Third Party Advisory","advisory","web"]},{"url":"https://github.com/paritytech/frontier/pull/549","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://github.com/paritytech/frontier/commit/8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2022-21685","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-cjg2-2fjg-fph4"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/21xxx/CVE-2022-21685.json","tags":["advisory"]},{"url":"https://github.com/paritytech/frontier","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2022-21685","title":"Integer underflow in Frontier","description":"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.","status":"published","published":"2022-01-14T17:05:11Z","modified":"2025-04-23T19:11:58.958Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-191"],"updated_at":"2026-11-02T14:34:29.057251Z"}],"euvd":[{"id":"EUVD-2022-0562","description":"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.","status":"published","published":"2022-01-14T17:05:11Z","modified":"2025-04-23T19:11:58Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T20:52:06.891582Z"}],"ghsa":[{"id":"GHSA-cjg2-2fjg-fph4","title":"Integer underflow in Frontier","description":"### Impact\n\nA 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.\n\nIf you do not use MODEXP precompile in your runtime, then you are not impacted.\n\n### Patches\n\nPatches are applied in PR #549.\n\n### Workarounds\n\nNone.\n\n### References\n\nPatch PR: #549\n\n### Credits\n\nThanks to SR-Labs for discovering the security vulnerability, and thanks to PureStake team for the patches.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n* Open an issue in the [Frontier repo](https://github.com/paritytech/frontier)\n","status":"published","published":"2022-01-14T21:03:36Z","modified":"2024-10-24T21:50:43Z","cwes":["CWE-191"],"updated_at":"2026-11-02T14:38:13.09489Z"}],"nvd":[{"id":"CVE-2022-21685","description":"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.","status":"published","published":"2022-01-14T17:15:13.333Z","modified":"2026-06-17T04:26:45.607Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":4,"vector":"AV:N/AC:L/Au:S/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-191"],"updated_at":"2026-11-02T14:07:10.836864Z"}],"osv":[{"id":"CVE-2022-21685","title":"Integer underflow in Frontier","description":"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.","status":"published","published":"2022-01-14T17:05:11Z","modified":"2026-10-28T02:30:34.016058029Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-191"],"updated_at":"2026-11-02T15:44:23.655778Z"},{"id":"GHSA-cjg2-2fjg-fph4","title":"Integer underflow in Frontier","description":"### Impact\n\nA 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.\n\nIf you do not use MODEXP precompile in your runtime, then you are not impacted.\n\n### Patches\n\nPatches are applied in PR #549.\n\n### Workarounds\n\nNone.\n\n### References\n\nPatch PR: #549\n\n### Credits\n\nThanks to SR-Labs for discovering the security vulnerability, and thanks to PureStake team for the patches.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n* Open an issue in the [Frontier repo](https://github.com/paritytech/frontier)\n","status":"published","published":"2022-01-14T21:03:36Z","modified":"2024-10-24T21:50:43Z","cwes":["CWE-191"],"updated_at":"2026-11-02T15:46:45.28161Z"}]}}