Vulnerability in Mozilla Firefox (CVE-2020-12401)
Summary
Vulnerability in Mozilla Firefox (CVE-2020-12401). Confidential information can be exposed externally.
Original description
The description as published by the source.
During ECDSA signature generation, padding applied in the nonce designed to ensure constant-time scalar multiplication was removed, resulting in variable-time execution dependent on secret data. This vulnerability affects Firefox < 80 and Firefox for Android < 80.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2020-12401 has been found in Mozilla Firefox.
Confidential information can be exposed externally. CVSS score: 4.7/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Mozilla Firefox CVE-2020-12401" on the vendor's site.
CVE-2020-12401 (Mozilla Firefox) — CWE-203 / CVSS v3 4.7
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-203) exists in Mozilla Firefox.
Check the vendor advisory for the affected versions of Mozilla Firefox.
Severity: Medium (CVSS 4.7/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Firefox' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Firefox' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Firefoxを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Alpine Linux ALPINE-CVE-2020-12401 nss Fixed in: 3.55-r0
References
- patch mozilla.org
- patch mozilla.org
- web bugzilla.mozilla.org
- web lists.debian.org
- web nvd.nist.gov
- web mozilla.org
- web mozilla.org
- web github.com