FirefoxWeb browser · Mozilla
CVE-2015-4485
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 · uneditedHeap-based buffer overflow in the resize_context_buffers function in libvpx in Mozilla Firefox before 40.0 and Firefox ESR 38.x before 38.2 allows remote attackers to execute arbitrary code via malformed WebM video data.
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 confidenceHeap-based buffer overflow vulnerability in libvpx's resize_context_buffers function allows remote attackers to execute arbitrary code via malformed WebM video files. The overflow occurs when handling specially crafted video data, enabling complete system compromise.
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
<= 39.0.3= 38.0= 38.0.1= 38.0.5= 38.1.0
Ubuntu LinuxOperating system
= 12.04= 14.04= 15.04= 13.1= 13.2= 11.3CVSS 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
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:N/AC:L/Au:N/C:C/I:C/A:C
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.
-
Check installed Firefox versionRun 'firefox --version' or go to Firefox > Help > About to see the exact version numberAffected if Version is 38.0, 38.0.1, 38.0.5, 38.1.0, or any version 39.0 through 39.0.3
-
Confirm WebM video support is enabledCheck Firefox add-ons and plugins for video handling capabilities, or verify the browser can play WebM files by attempting to play a known WebM fileAffected if WebM video playback is functional in the Firefox installation
-
Verify libvpx library versionOn Linux systems, run 'dpkg -l | grep libvpx' (Ubuntu) or 'rpm -qa | grep libvpx' (OpenSUSE) to list the installed libvpx package versionAffected if libvpx version matches the version bundled with affected Firefox releases (typically 1.3.x series)
User is likely affected if Firefox version matches 38.0, 38.0.1, 38.0.5, 38.1.0, or any 39.x version up to 39.0.3 and the browser is used to handle WebM video content.
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 · scopedUpdate Mozilla Firefox to version 40.0 or later (or Firefox ESR to 38.2 or later) to include the patched libvpx library. Until updated, do not open untrusted WebM video content in Firefox.
Firefox 40.0+ or Firefox ESR 38.2+
- Upgrade Firefox to version 40.0 or later
- For Firefox ESR users, upgrade to version 38.2 or later
- Apply system package updates via package manager (apt-get update && apt-get upgrade for Ubuntu, zypper update for OpenSUSE) to receive the patched Firefox packages
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Firefox
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 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 $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-4485 — 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 sources- www.mozilla.org
- lists.opensuse.org
- lists.opensuse.org
- www.oracle.com
- www.ubuntu.com
- www.ubuntu.com
- bugzilla.mozilla.org
- lists.opensuse.org
- lists.opensuse.org
- lists.opensuse.org
- lists.opensuse.org
- lists.opensuse.org
- rhn.redhat.com
- www.securitytracker.com
- www.ubuntu.com
- security.gentoo.org
- nvd.nist.gov
Practitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2015-4485 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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