FirefoxWeb browser · Mozilla
CVE-2016-9066
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 buffer overflow resulting in a potentially exploitable crash due to memory allocation issues when handling large amounts of incoming data. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.
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 buffer overflow vulnerability in Mozilla Firefox, Thunderbird, and Firefox ESR exists due to improper memory allocation handling when processing large amounts of incoming data. This can cause a potentially exploitable crash, allowing remote attackers to execute arbitrary code or cause denial of service.
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
< 45.5.0< 50.0
Debian LinuxOperating system
= 8.0< 45.5.0CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 Firefox versionOpen Firefox, click the menu icon (three horizontal lines), select Help, then About Firefox. The version number is displayed in the window that opens.Affected if The displayed version is less than 50.0 (for example, 49.2, 45.4, etc.)
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Identify installed Thunderbird versionOpen Thunderbird, click the menu icon, select Help, then About Thunderbird. The version number is displayed in the window that opens.Affected if The displayed version is less than 45.5.0 (for example, 45.4.2, 38.x, etc.)
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Check Firefox ESR version on LinuxOpen a terminal and run: firefox --version or dpkg -l | grep firefox-esr to see the installed ESR version and package details.Affected if The version shown is less than 45.5.0 (for example, 45.4.x ESR, 38.x ESR, etc.)
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Confirm OS version on Debian systemsRun: cat /etc/debian_version or lsb_release -a to determine the Debian release number.Affected if The system is running Debian 8.0 and has an affected Firefox or Thunderbird version installed.
You are affected if you are running any version of Firefox below 50.0, any version of Thunderbird below 45.5.0, or any version of Firefox ESR below 45.5.0 on Debian 8.0.
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 data45.5.050.0
Update affected products to the patched versions: Thunderbird to 45.5+, Firefox ESR to 45.5+, and Firefox to 50 or higher.
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-2016-9066 — 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-2016-9066 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