FirefoxWeb browser · Mozilla
CVE-2023-37207
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 · uneditedA website could have obscured the fullscreen notification by using a URL with a scheme handled by an external program, such as a mailto URL. This could have led to user confusion and possible spoofing attacks. This vulnerability affects Firefox < 115, Firefox ESR < 102.13, and Thunderbird < 102.13.
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 confidenceA web page can navigate to a URL using an external protocol handler scheme (such as mailto:) which causes the browser's fullscreen notification warning to be obscured or hidden. This UI spoofing issue allows malicious sites to potentially trick users about the true fullscreen state of the browser window.
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
< 115.0
Firefox EsrWeb browser
< 102.13
Debian LinuxOperating system
= 10.0= 11.0= 12.0< 102.13CVSS 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
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/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.
-
Check Firefox versionIn Firefox, go to Menu > Help > About Firefox, or enter 'about:support' in the address bar. Note the version number shown.Affected if Version is below 115.0 (for example, 114.x, 113.x, etc.)
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Check Firefox ESR versionIn Firefox ESR, go to Menu > Help > About Firefox, or enter 'about:support' in the address bar. Look for 'Firefox ESR' label and note the version number.Affected if Version is below 102.13 (for example, 102.12, 102.11, etc.)
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Check Thunderbird versionIn Thunderbird, go to Menu > Help > About Thunderbird. Note the version number shown.Affected if Version is below 102.13 (for example, 102.12, 102.11, etc.)
If you have Firefox below 115.0, Firefox ESR below 102.13, or Thunderbird below 102.13, and you use fullscreen mode while browsing, your browser could be exploited to hide the fullscreen notification warning via external protocol handlers like mailto: URLs.
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 · scoped102.13115.0
Update affected applications to patched versions: Firefox 115+, Firefox ESR 102.13+, or Thunderbird 102.13+.
Firefox 115.0, Firefox ESR 102.13, or Thunderbird 102.13
- Check current Firefox/Thunderbird version by navigating to about:support in the browser
- For system package managers: Update package lists with 'apt update' or equivalent
- Upgrade Firefox to version 115.0 or later using system package manager or download from mozilla.org
- Upgrade Firefox ESR to version 102.13 or later
- Upgrade Thunderbird to version 102.13 or later
- Restart the application after upgrade
- Verify the fix by checking the installed version matches or exceeds the fixed release
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Firefox
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 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 $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-37207 — 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-2023-37207 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