CVE-2022-21685: Frontier is Substrate's Ethereum compatibility layer

Q: How do I fix CVE-2022-21685?

frontier: upgrade to newer than 2022-01-13. Exact commands for each OS are on this page.

Q: Is CVE-2022-21685 being exploited?

CVE-2022-21685 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2022-21685 affect?

CVE-2022-21685 affects frontier. Severity is medium (CVSS 6.5). 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 ca

Q: How urgent is CVE-2022-21685?

Priority 41/100. No elevated risk signals yet.

This month

MEDIUM 6.5UPGRADE

CVE-2022-21685 is a medium-severity flaw (CVSS 6.5) affecting frontier. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 r

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.3% (top 29%)
CISA exploited list	No
Weakness	CWE-191
Published	2022-01-14
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: parity

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-01-14 17:15 UTCPublished CVE record published
2026-06-17 04:26 UTCUpdated Record last modified

parity frontier UPGRADE

Affected: <= 2022-01-13

Fixed in: newer than 2022-01-13

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy frontier || rpm -q frontier || frontier --version

2. UPGRADE to newer than 2022-01-13 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade frontier

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade frontier

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2022-21685?

frontier: upgrade to newer than 2022-01-13. Exact commands for each OS are on this page.

Is CVE-2022-21685 being exploited?

CVE-2022-21685 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2022-21685 affect?

CVE-2022-21685 affects frontier. Severity is medium (CVSS 6.5). 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 ca

How urgent is CVE-2022-21685?

Priority 41/100. No elevated risk signals yet.

Related CVEs

CVE-2023-45130 HIGH 7.5 UPGRADE Frontier is Substrate's Ethereum compatibility layer
CVE-2023-28431 HIGH 7.5 UPGRADE Frontier is an Ethereum compatibility layer for Substrate
CVE-2022-39242 MEDIUM 5.3 UPGRADE Frontier is an Ethereum compatibility layer for Substrate
CVE-2022-36008 HIGH 7.1 MITIGATE Frontier is Substrate's Ethereum compatibility layer
CVE-2022-31111 MEDIUM 5.3 MITIGATE Frontier is Substrate's Ethereum compatibility layer

References

← Back to latest CVEs