FirefoxWeb browser · Mozilla

CVE-2010-3766

HIGH · 9.3 CVSS v2.0 Published 2010-12-10

Fix available

A fix is available. Upgrade to after 3.5.15 or later.

See remediation →

100/100

Remediation priority · Urgent

Remotely reachable No privileges Zero-click

Official description

NVD · unedited

Use-after-free vulnerability in Mozilla Firefox before 3.5.16 and 3.6.x before 3.6.13, and SeaMonkey before 2.0.11, allows remote attackers to execute arbitrary code via vectors involving a change to an nsDOMAttribute node.

Technical summary

dbcve analysis · high confidence

Use-after-free vulnerability in Mozilla Firefox (versions before 3.5.16 and 3.6.x before 3.6.13) and SeaMonkey (before 2.0.11) allows remote attackers to execute arbitrary code via vectors involving manipulation of nsDOMAttribute nodes.

MitigationUpdate affected browser installations to Firefox 3.5.16/3.6.13 or SeaMonkey 2.0.11 or later to remediate this vulnerability.

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:= 3.6= 3.6.2= 3.6.3= 3.6.4= 3.6.6= 3.6.7= 3.6.8= 3.6.9= 3.6.10= 3.6.11= 3.6.12<= 3.5.15

SeamonkeyApplication

Affected:= 1.0= 1.0.1= 1.0.2= 1.0.3= 1.0.4= 1.0.5= 1.0.6= 1.0.7= 1.0.8= 1.0.9= 1.1= 1.1.1

CVSS breakdown

From the vector

Attack vector: Network
Complexity: M
Authentication: None
Confidentiality: Complete
Integrity: Complete
Availability: Complete

AV:N/AC:M/Au:N/C:C/I:C/A:C

Am I affected?

dbcve checks

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

Identify installed Firefox version

Open Firefox and navigate to Help > About Mozilla Firefox, or type 'about:version' in the address bar. On Linux, run 'firefox --version' in terminal. On Windows, check 'C:\Program Files\Mozilla Firefox\firefox.exe' properties or use Add/Remove Programs.

Affected if The reported version is 3.6, 3.6.2, 3.6.3, 3.6.4, 3.6.6, 3.6.7, 3.6.8, 3.6.9, 3.6.10, 3.6.11, 3.6.12, or any 3.5.x version up to and including 3.5.15
Identify installed SeaMonkey version

Open SeaMonkey and navigate to Help > About SeaMonkey, or type 'about:version' in the address bar. On Linux, run 'seamonkey --version' in terminal. On Windows, check 'C:\Program Files\SeaMonkey\seamonkey.exe' properties or use Add/Remove Programs.

Affected if The reported version is 1.0.x (any 1.0 through 1.0.9), 1.1, or 1.1.1

A user is affected if they have Firefox version 3.6.x before 3.6.13, Firefox 3.5.x before 3.5.16, or SeaMonkey version 1.0.x/1.1.x before 2.0.11 installed.

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

Remediation

dbcve · scoped

Upgrade available Upgrade to a release after 3.5.15

Interim mitigation

Update affected browser installations to Firefox 3.5.16/3.6.13 or SeaMonkey 2.0.11 or later to remediate this vulnerability.

Recommended fix High confidence

Firefox 3.6.x → Firefox 3.6.13 (or migrate to Firefox 115+ ESR); SeaMonkey 1.x → SeaMonkey 2.0.11

Verify current browser version by navigating to Help > About Firefox or About SeaMonkey
Download Firefox 3.6.13 or later from mozilla.org (or upgrade to a currently supported Firefox version like Firefox 115+ ESR for extended support)
Download SeaMonkey 2.0.11 or later from mozilla.org (or migrate to a currently supported browser)
Close all Firefox/SeaMonkey instances
Install the upgraded browser version
Restart the browser and verify the version in Help > About

Caveat These are very old browser versions with no modern security features; upgrading may break compatibility with legacy websites and plugins; consider migrating to a currently supported browser (Firefox 115+ ESR or Firefox 128+) for ongoing security updates

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Firefox Scoped from the published advisory

Consultation2.0 h
Implementation3.0 h
Testing1.0 h
Review / QA2.0 h

8.0 hours of engineering $1,450

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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-2010-3766 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2010-3766?

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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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 3.5.15 or later

Severity 9.3 High

Exploit likelihood EPSS, next 30 days 7.0%

Affects: Firefox

Remediation

A high-priority fix

Fix this in Firefox 8 hrs · Low

Typical engagement from $1,450

Get a fix See the full breakdown ↓

A high-priority vulnerability. Send your environment and a specialist will scope CVE-2010-3766 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