FirefoxWeb browser · Mozilla
CVE-2024-6612
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 · uneditedCSP violations generated links in the console tab of the developer tools, pointing to the violating resource. This caused a DNS prefetch which leaked that a CSP violation happened. This vulnerability affects Firefox < 128 and Thunderbird < 128.
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 confidenceCSP violations in Firefox and Thunderbird generate clickable links in the developer tools console pointing to violating resources. The browser automatically performs DNS prefetching on these links, causing DNS queries that leak the fact a CSP violation occurred to DNS observers (such as ISPs or DNS logging services). This defeats the purpose of CSP as a security mechanism by revealing violation details.
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
< 128.0< 128.0CVSS 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
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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.
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Check Firefox versionOpen Firefox, click the menu button (three horizontal lines), go to Help > About Firefox. The version number is displayed on this page.Affected if The displayed version is earlier than 128.0 (e.g., 127.x, 126.x, etc.)
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Check Thunderbird versionOpen Thunderbird, click the menu button (three horizontal lines), go to Help > About Thunderbird. The version number is displayed on this page.Affected if The displayed version is earlier than 128.0 (e.g., 127.x, 126.x, etc.)
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Verify version via command line (optional)On Windows, run 'firefox -v' or 'thunderbird -v' from Command Prompt or PowerShell. On macOS, run '/Applications/Firefox.app/Contents/MacOS/firefox -v' or '/Applications/Thunderbird.app/Contents/MacOS/thunderbird -v' in Terminal.Affected if The returned version number is less than 128.0
You are affected if any installed instance of Firefox or Thunderbird shows a version number below 128.0, as versions prior to 128.0 contain the DNS prefetch leak in CSP violation console links.
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 · scoped128.0
Update Firefox and Thunderbird to version 128 or later to receive the security patch.
Firefox 128.0 and Thunderbird 128.0
- Upgrade Firefox to version 128.0 or later
- Upgrade Thunderbird to version 128.0 or later
- Restart the application after upgrading
- Verify the version by checking Help > About Firefox or Help > About Thunderbird
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Firefox
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-6612 — 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-2024-6612 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
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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