dbcve.org
SafariWeb browser · Apple

CVE-2018-4186

HIGH · 7.5 CVSS v3.0 Published 2019-01-11
Fix available
A fix is available. Upgrade to 11.1 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
In Safari before 11.1, an information leakage issue existed in the handling of downloads in Safari Private Browsing. This issue was addressed with additional validation.

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 · moderate confidence

An information disclosure vulnerability in Safari versions before 11.1 allowed download history or file details to leak when using Private Browsing mode. The browser failed to properly validate download-related data, potentially exposing information that should have remained protected during private browsing sessions.

MitigationUpgrade Safari to version 11.1 or later, which includes additional validation logic to prevent download information leakage in Private Browsing mode.

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
SafariWeb browser
Affected:< 11.1

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.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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 checks

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

  1. Identify installed Safari version
    Open Safari, click Safari menu > About Safari (on Mac) or go to Settings > Safari > About (on iOS) to display the full version number
    Affected if The displayed version number is lower than 11.1 (for example, 11.0.x, 10.1.x, or earlier)
  2. Confirm Private Browsing is in use
    Open a new Private Browsing window by clicking File > New Private Window (Mac) or tapping the tabs icon > Private (iOS), then initiate a download within this session
    Affected if You are able to perform downloads while in Private Browsing mode with a Safari version below 11.1
  3. Inspect download behavior in Private mode
    With Safari below 11.1 open in Private Browsing mode, download a file and observe whether download history or file metadata becomes visible outside the private session or persists after closing the Private Browsing window
    Affected if Download information (file name, path, size, or download timestamp) remains accessible after closing the Private Browsing session or is exposed to other browsing modes

You are affected if your Safari version is below 11.1 and you use Private Browsing mode to download files, as download-related information may leak and persist beyond the private session.

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

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Upgrade available Upgrade to 11.1 or later
Fixed in 11.1
Interim mitigation

Upgrade Safari to version 11.1 or later, which includes additional validation logic to prevent download information leakage in Private Browsing mode.

Fix this in Safari Scoped from the published advisory
  • Consultation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-4186 in production — separate from our analysis above.

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