FirefoxWeb browser · Mozilla
CVE-2019-9818
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 · uneditedA race condition is present in the crash generation server used to generate data for the crash reporter. This issue can lead to a use-after-free in the main process, resulting in a potentially exploitable crash and a sandbox escape. *Note: this vulnerability only affects Windows. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.
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 confidenceA race condition in the crash generation server allows an attacker to trigger a use-after-free vulnerability in the main process, potentially enabling a sandbox escape on Windows systems. This affects Firefox, Firefox ESR, and Thunderbird versions prior to the patches.
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
< 67.0
Firefox EsrWeb browser
< 60.7< 60.7CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
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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Identify installed Mozilla productCheck for presence of Firefox, Firefox ESR, or Thunderbird in installed programs or by running: 'firefox --version', 'firefox-esr --version', or 'thunderbird --version'Affected if Any of these products are installed and version is below 67.0 for Firefox, below 60.7 for Firefox ESR, or below 60.7 for Thunderbird
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Check Firefox versionRun 'firefox --version' or navigate to about:Firefox in the browser address barAffected if Version is lower than 67.0
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Check Firefox ESR versionRun 'firefox-esr --version' or navigate to about:Firefox in the browser address barAffected if Version is lower than 60.7
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Check Thunderbird versionRun 'thunderbird --version' or navigate to about:Thunderbird in the applicationAffected if Version is lower than 60.7
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Verify crash reporter is enabled (vulnerable component)In Firefox/Thunderbird, go to about:support and look for 'Crash Reports' section, or check if the crashpad handler is running in processesAffected if Crash reporter is enabled and the version is within the affected range
A user is affected if they have Firefox below 67.0, Firefox ESR below 60.7, or Thunderbird below 60.7 installed with the crash reporter enabled on Windows systems.
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.
From vendor data60.767.0
Upgrade to Firefox 67, Firefox ESR 60.7, Thunderbird 60.7 or later to address the race condition and use-after-free vulnerability.
Fix this in Firefox
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 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 $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-9818 — 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-2019-9818 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
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