FirefoxWeb browser · Mozilla

CVE-2014-1576

HIGH · 7.5 CVSS v2.0 Published 2014-10-15

Fix available

A fix is available. Upgrade to after 32.0 or later.

See remediation →

84/100

Remediation priority · High

Remotely reachable No privileges Zero-click

Official description

NVD · unedited

Heap-based buffer overflow in the nsTransformedTextRun function in Mozilla Firefox before 33.0, Firefox ESR 31.x before 31.2, and Thunderbird 31.x before 31.2 allows remote attackers to execute arbitrary code via Cascading Style Sheets (CSS) token sequences that trigger changes to capitalization style.

Technical summary

dbcve analysis · high confidence

Heap-based buffer overflow in Mozilla Firefox and Thunderbird's nsTransformedTextRun function when processing CSS token sequences that modify text capitalization (e.g., text-transform: uppercase). The vulnerability allows remote attackers to execute arbitrary code via specially crafted web pages or emails containing malicious CSS.

MitigationUpdate affected products to Firefox 33.0, Firefox ESR 31.2, Thunderbird 31.2 or later. Avoid browsing untrusted websites or opening suspicious email content until patches are applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

FirefoxWeb browser

Affected:= 31.0= 31.1.0<= 32.0= 30.0

ThunderbirdApplication

Affected:= 31.0= 31.1.0

CVSS breakdown

From the vector

Attack vector: Network
Complexity: Low
Authentication: None
Confidentiality: Partial
Integrity: Partial
Availability: Partial

AV:N/AC:L/Au:N/C:P/I:P/A:P

Am I affected?

dbcve checks

Work through these to decide whether this CVE applies to you.

Identify if Mozilla Firefox is installed

Check for Firefox installation: On Windows, look in Program Files for Firefox folder, or check registry HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Mozilla Firefox. On Linux, run 'which firefox' or check package manager. On Mac, check /Applications/Firefox.app.

Affected if Firefox is installed and version is 30.0, 31.0, 31.1.0, or 32.0 or lower
Identify if Mozilla Thunderbird is installed

Check for Thunderbird installation: On Windows, look in Program Files for Thunderbird folder. On Linux, run 'which thunderbird' or check package manager. On Mac, check /Applications/Thunderbird.app.

Affected if Thunderbird is installed and version is 31.0 or 31.1.0
Confirm exact Firefox version

In Firefox, navigate to Help > About Firefox, or run 'firefox --version' from command line, or check the version file in the Firefox installation directory.

Affected if Version equals 30.0, 31.0, 31.1.0, or is 32.0 or lower (for example 32.0, 31.2, 31.1, 31.0.1, 30.1, 30.0.1)
Confirm exact Thunderbird version

In Thunderbird, navigate to Help > About Thunderbird, or run 'thunderbird --version' from command line.

Affected if Version equals 31.0 or 31.1.0

A user is affected if they have Firefox version 30.0, 31.0, 31.1.0, or 32.0 or lower, or Thunderbird version 31.0 or 31.1.0 installed on their system.

Generated from the published advisory. Verify against your own configuration.

Remediation

From vendor data

Upgrade available Upgrade to a release after 32.0

Interim mitigation

Update affected products to Firefox 33.0, Firefox ESR 31.2, Thunderbird 31.2 or later. Avoid browsing untrusted websites or opening suspicious email content until patches are applied.

Fix this in Firefox Scoped from the published advisory

Consultation2.0 h
Implementation4.0 h
Testing2.0 h
Review / QA1.0 h

9.0 hours of engineering $1,600

Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

Free · runs locally

dbcve dependency scanner

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References

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2014-1576 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2014-1576?

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.

What this is

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.

What belongs here

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

At a glance

A fix existsUpgrade to after 32.0 or later

Severity 7.5 High

Exploit likelihood EPSS, next 30 days 5.1%

Affects: Firefox

Remediation

A high-priority fix

Fix this in Firefox 9 hrs · Low

Typical engagement from $1,600

Get a fix See the full breakdown ↓

A high-priority vulnerability. Send your environment and a specialist will scope CVE-2014-1576 and return a fixed quote and timeline.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

CVSS 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.

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.

Check your environment

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.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References