FirefoxWeb browser · Mozilla
CVE-2016-9077
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 · uneditedCanvas allows the use of the "feDisplacementMap" filter on images loaded cross-origin. The rendering by the filter is variable depending on the input pixel, allowing for timing attacks when the images are loaded from third party locations. This vulnerability affects 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 confidenceFirefox's Canvas implementation allows the feDisplacementMap filter to render cross-origin images with variable timing based on pixel content. This timing variation enables attackers to infer pixel values from protected images by measuring render times, bypassing Same-Origin Policy protections through a side-channel timing attack.
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
< 50.0CVSS 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
- Local
- Complexity
- High
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:L/AC:H/PR:N/UI:R/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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Determine installed Firefox versionOpen Firefox and navigate to about:support, or click Help > About Firefox. Locate the version number displayed on the page.Affected if The version number is less than 50.0 (for example, 49.x or earlier)
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Confirm Canvas feature is enabledIn the Firefox address bar, type about:config and press Enter. In the search filter, type html.canvas.enabled. Verify the preference value is set to true.Affected if html.canvas.enabled is true (this is the default setting)
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Verify cross-origin image loading is permittedCheck that the browser has not been configured to block cross-origin images. This is the default behavior in vulnerable versions - no special configuration needed for the attack to succeed.Affected if Cross-origin images can be loaded and rendered in Canvas (default behavior in vulnerable versions)
The environment is affected if Firefox version is below 50.0 and the Canvas feature remains enabled with default cross-origin loading permissions.
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 data50.0
Upgrade Firefox to version 50 or later. Alternatively, configure browsers to block cross-origin image loading or disable Canvas features if upgrading is not feasible.
Fix this in Firefox
Scoped from the published advisory
- Consultation1.0 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 $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-9077 — 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-2016-9077 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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- 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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