FirefoxWeb browser · Mozilla
CVE-2009-3988
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 · uneditedMozilla Firefox 3.0.x before 3.0.18 and 3.5.x before 3.5.8, and SeaMonkey before 2.0.3, does not properly restrict read access to object properties in showModalDialog, which allows remote attackers to bypass the Same Origin Policy and conduct cross-site scripting (XSS) attacks via crafted dialogArguments values.
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 confidenceThe showModalDialog JavaScript function in Firefox 3.0.x before 3.0.18 and 3.5.x before 3.5.8 (and SeaMonkey before 2.0.3) improperly restricts read access to object properties passed via dialogArguments. This allows a malicious page to access properties of cross-origin dialog content, bypassing the Same Origin Policy and enabling XSS attacks.
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
<= 3.0.17= 3.0= 3.0.1= 3.0.2= 3.0.3= 3.0.4= 3.0.5= 3.0.6= 3.0.7= 3.0.8= 3.0.9= 3.0.10= 2.0CVSS 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
- Network
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- None
- Availability
- None
AV:N/AC:L/Au:N/C:P/I:N/A:N
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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Identify Firefox browser versionOpen Firefox, click Help > About Firefox (or navigate to about:support). Note the version number displayed (for example, 3.0.17, 3.5.7, or 3.0.18).Affected if Version is 3.0.x through 3.0.17, or 3.5.x through 3.5.7 (versions below 3.0.18 or 3.5.8)
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Identify SeaMonkey browser versionOpen SeaMonkey, click Help > About SeaMonkey. Note the version number displayed (for example, 2.0, 2.0.1, 2.0.2, or 2.0.3).Affected if Version is 2.0, 2.0.1, or 2.0.2 (versions below 2.0.3)
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Confirm browser vendor and buildCheck the application name and build information in the About dialog to confirm it is genuine Mozilla Firefox or SeaMonkey (not a third-party fork with independent versioning).Affected if The browser is a Mozilla product with version matching the affected ranges above
A user is affected if they are running Firefox 3.0.x (through 3.0.17), Firefox 3.5.x (through 3.5.7), or SeaMonkey 2.0.x (through 2.0.2) and use the showModalDialog function in web content, as the Same Origin Policy bypass allows cross-origin property access via dialogArguments.
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 affected browsers to Firefox 3.0.18+, 3.5.8+, or SeaMonkey 2.0.3+ (or later versions). In enterprise environments, deploy updated browsers organization-wide via patch management.
Fix this in Firefox
Scoped from the published advisory
- Consultation2.0 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-2009-3988 — 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- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.opensuse.org
- secunia.com
- secunia.com
- www.debian.org
- www.mandriva.com
- www.mozilla.org
- www.redhat.com
- www.ubuntu.com
- www.ubuntu.com
- www.vupen.com
- bugzilla.mozilla.org
- exchange.xforce.ibmcloud.com
- oval.cisecurity.org
- oval.cisecurity.org
- nvd.nist.gov
Practitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2009-3988 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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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