FirefoxWeb browser · Mozilla
CVE-2017-7780
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 · uneditedMemory safety bugs were reported in Firefox 54. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 55.
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 · moderate confidenceMemory safety bugs in Firefox 54 lead to memory corruption that could potentially allow arbitrary code execution. This is a critical client-side vulnerability in the Firefox browser affecting versions prior to 55.
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
< 55.0CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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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Confirm Firefox is installedLocate the Firefox browser executable or check system installed programs. On Windows, check Program Files or Program Files (x86) for Mozilla Firefox folder. On macOS, check /Applications for Firefox.app. On Linux, run 'which firefox' or check /usr/lib/firefox.Affected if Firefox browser is not installed on the system
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Determine installed Firefox versionOpen Firefox, click the menu button (three horizontal lines), select Help, then About Firefox. The version number will be displayed in the window that opens. Alternatively, from command line run 'firefox --version' on Linux/macOS or check the executable properties on Windows.Affected if The version shown is below 55.0 (for example, 54.x, 53.x, etc.)
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Verify browser is actively usedConfirm that the installed Firefox version is the primary or secondary browser in regular use, or that it exists as a configured browser on the system.Affected if Firefox below version 55 is installed and configured for use
A user is affected if they have Mozilla Firefox installed with a version number less than 55.0, as this is the specific version range identified as vulnerable to CVE-2017-7780.
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 · scoped55.0
Upgrade Firefox to version 55 or later to remediate this vulnerability.
Firefox 55.0 or later
- 1. Back up any important bookmarks, passwords, and settings from the current Firefox installation
- 2. Open Firefox and navigate to the Help menu (or access Firefox settings)
- 3. Select 'About Firefox' to check the current version
- 4. Click 'Check for Updates' to download and install Firefox 55.0 or later
- 5. Restart Firefox after the update completes
- 6. Verify the version by going to Help > About Firefox - it should show 55.0 or higher
- 7. Alternatively, download Firefox 55.0 or later directly from the official Mozilla website (www.mozilla.org) and install over the current version
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-2017-7780 — 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-2017-7780 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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