FirefoxWeb browser · Mozilla
CVE-2020-12413
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe Raccoon attack is a timing attack on DHE ciphersuites inherit in the TLS specification. To mitigate this vulnerability, Firefox disabled support for DHE ciphersuites.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Raccoon attack is a timing attack targeting DHE (Diffie-Hellman Ephemeral) ciphersuites in TLS, exploiting subtle timing differences in the server's processing of the DHE key exchange to potentially recover the premaster secret. This vulnerability is inherent in the TLS specification itself rather than being specific to a particular implementation. Firefox mitigated this by disabling all DHE ciphersuites.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FirefoxWeb browser
< 78.0
Firefox EsrWeb browser
< 68.10.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Check Firefox versionOpen Firefox, click the menu button, go to Help > About Firefox. The version number will be displayed.Affected if Version is below 78.0 (or ESR below 68.10.0 for Firefox ESR)
-
Inspect TLS cipher configurationType 'about:config' in the address bar, search for 'tls.version' and 'security.tls' settings to review enabled TLS versions and cipher suites.Affected if DHE-based ciphersuites (such as TLS_DHE_*) are present and enabled in the configuration
-
Verify DHE ciphersuite support via browser testVisit a TLS testing site (such as ssllabs.com/ssltest) using the Firefox browser to see which ciphersuites the browser offers during TLS handshake.Affected if The test结果显示浏览器支持DHE相关的加密套件（如TLS_DHE_RSA_WITH_AES_256_GCM_SHA384等）
如果火狐浏览器版本低于78.0（或ESR版本低于68.10.0）并且TLS配置中启用了DHE加密套件，则该环境受CVE-2020-12413影响。
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped68.10.078.0
Disable DHE ciphersuites and ensure only ECDHE (Elliptic Curve Diffie-Hellman Ephemeral) or other timing-safe ciphersuites are enabled in TLS configurations. Verify client compatibility with the disabled DHE support.
Firefox 78.0 or later, Firefox ESR 68.10.0 or later
- 1. Open Firefox and navigate to the menu (three horizontal lines in the top-right corner)
- 2. Click on Help > About Firefox
- 3. The About Firefox window will check for updates and display the current version
- 4. If an update is available, click 'Restart to Update Firefox' to apply the update
- 5. Verify the update was successful by returning to Help > About Firefox and confirming the version is 78.0 or later (or 68.10.0 or later for ESR)
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Firefox
Scoped from the published advisory
- Consultation3.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,072.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-12413 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-12413 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data