FirefoxWeb browser · Mozilla
CVE-2015-7195
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 · uneditedThe URL parsing implementation in Mozilla Firefox before 42.0 improperly recognizes escaped characters in hostnames within Location headers, which allows remote attackers to obtain sensitive information via vectors involving a redirect.
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 confidenceMozilla Firefox before version 42.0 has a flaw in its URL parsing implementation where escaped characters in hostnames within HTTP Location headers are improperly recognized. This allows remote attackers to manipulate redirect behavior and potentially obtain sensitive information through specially crafted redirect responses.
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
<= 41.0.2CVSS 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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Check Firefox version on WindowsOpen Firefox, click the menu button (three horizontal lines), then click Help > About Firefox. The version number is displayed in the window that opens.Affected if The version number shown is 41.0.2 or lower
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Check Firefox version on macOSOpen Firefox, click Firefox in the menu bar, then select About Firefox. The version number is displayed in the window that opens.Affected if The version number shown is 41.0.2 or lower
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Check Firefox version on LinuxOpen a terminal and run: firefox --version OR go to Firefox > Help > About Firefox from the application menu.Affected if The version number shown is 41.0.2 or lower
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Check Firefox version via about:supportType about:support in the Firefox address bar and press Enter. Locate the 'Version' field in the 'Application Basics' section.Affected if The version displayed is 41.0.2 or lower
If the installed Firefox version is 41.0.2 or earlier, the browser is affected by this URL parsing vulnerability in Location header handling.
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 Firefox to version 42.0 or later, which contains the fix for proper escaped character handling in hostname parsing. Applications should validate all redirect targets server-side before issuing Location headers.
Fix this in Firefox
Scoped from the published advisory
- Consultation4.0 h
- Implementation2.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,928.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-7195 — 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-2015-7195 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
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