FirefoxWeb browser · Mozilla
CVE-2015-4512
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 · uneditedgfx/2d/DataSurfaceHelpers.cpp in Mozilla Firefox before 41.0 on Linux improperly attempts to use the Cairo library with 32-bit color-depth surface creation followed by 16-bit color-depth surface display, which allows remote attackers to obtain sensitive information from process memory or cause a denial of service (out-of-bounds read) by using a CANVAS element to trigger 2D rendering.
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 confidenceMozilla Firefox before 41.0 on Linux contains a memory safety vulnerability in gfx/2d/DataSurfaceHelpers.cpp where the Cairo graphics library is improperly used with mismatched color depths—creating 32-bit surfaces but attempting to display them as 16-bit. This mismatch causes out-of-bounds memory reads when rendering via CANVAS elements, allowing remote attackers to potentially read sensitive process memory or crash the browser.
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
<= 40.0.3CVSS 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
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:P/I:N/A:P
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 installed Firefox version on LinuxOpen terminal and run: firefox --version OR go to Firefox menu > Help > About FirefoxAffected if Version displayed is 40.0.3 or earlier (any version <= 40.0.3) on a Linux system
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Confirm operating system is LinuxRun: uname -a OR cat /etc/os-releaseAffected if OS is Linux (this vulnerability only affects Firefox on Linux, not Windows or macOS)
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Verify JavaScript is enabledIn Firefox address bar, type: about:config, search for javascript.enabled, or check in Options > ContentAffected if JavaScript is enabled (CANVAS element rendering requires JavaScript to trigger the vulnerable code path)
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Check if CANVAS rendering is accessibleVisit any webpage with CANVAS elements (e.g., html5canvastutorial.com) or check if local/web CANVAS content can be renderedAffected if Browser can render CANVAS elements - the vulnerability is triggered through CANVAS rendering with mismatched color depths in the Cairo graphics library
You are affected if running Firefox version 40.0.3 or earlier on Linux with JavaScript enabled and the ability to render CANVAS content, as the flaw lies in gfx/2d/DataSurfaceHelpers.cpp when Cairo renders 32-bit surfaces as 16-bit.
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 dataUpgrade to Mozilla Firefox 41.0 or later. Until then, disable JavaScript or restrict rendering of untrusted CANVAS content to reduce attack surface.
Fix this in Firefox
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,192.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-4512 — 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-2015-4512 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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