FirefoxWeb browser · Mozilla
CVE-2019-11737
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 · uneditedIf a wildcard ('*') is specified for the host in Content Security Policy (CSP) directives, any port or path restriction of the directive will be ignored, leading to CSP directives not being properly applied to content. This vulnerability affects Firefox < 69.
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 confidenceIn Firefox versions before 69, when a wildcard ('*') is specified as the host in Content Security Policy (CSP) directives, any port or path restrictions defined in that directive are ignored. This means CSP rules intended to restrict content to specific ports or paths become ineffective, potentially allowing content from unintended sources to be loaded.
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
< 69.0CVSS 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
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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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Check Firefox versionNavigate to Firefox menu > Help > About Firefox, or enter 'about:support' in the address bar to see the version numberAffected if Version is less than 69.0 (e.g., 68.x, 67.x, etc.)
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Identify CSP headers with wildcard hostsUse browser DevTools (F12) > Network tab, or inspect HTTP response headers for 'Content-Security-Policy' entries containing '*' as the host sourceAffected if CSP policy contains '*' as host in any directive (default-src, script-src, style-src, etc.) and also specifies port or path restrictions (e.g., '*:8443' or '*/api')
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Review custom CSP policies in web applicationsIf you manage a web application, audit its deployed CSP headers and meta tags for patterns like '*://example.com:8080/*' or '*' combined with port/path modifiersAffected if Your application serves CSP headers using wildcard '*' host with explicit port numbers or path prefixes
You are affected if you run Firefox version below 69 AND either browse sites with CSP wildcards that include port/path constraints, or serve a web application using CSP with wildcard hosts plus port/path restrictions.
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 data69.0
Update Firefox to version 69 or later. Alternatively, avoid using wildcard '*' for hosts in CSP directives and instead specify exact hostnames when port or path restrictions are required.
Fix this in Firefox
Scoped from the published advisory
- Consultation1.0 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-2019-11737 — 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-2019-11737 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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- 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
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