dbcve.org
SafariWeb browser · Apple

CVE-2018-4133

MEDIUM · 6.1 CVSS v3.0 Published 2018-04-03
Fix available
A fix is available. Upgrade to 2.20.4 / 11.1 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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
An issue was discovered in certain Apple products. Safari before 11.1 is affected. The issue involves the "WebKit" component. A Safari cross-site scripting (XSS) vulnerability allows remote attackers to inject arbitrary web script or HTML via a crafted URL.

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 confidence

A cross-site scripting (XSS) vulnerability in WebKit allows remote attackers to inject arbitrary web script or HTML via a crafted URL. The vulnerability affects Safari versions prior to 11.1, enabling attackers to potentially execute malicious client-side code in the context of a user's browsing session.

MitigationUpgrade Safari to version 11.1 or later to remediate this vulnerability. Organizations should deploy the update via their device management or patch management infrastructure.

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
Ubuntu LinuxOperating system
Affected:= 16.04= 17.10
Webkitgtk\+Web browser
Affected:< 2.20.4

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
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

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

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

  1. Check Safari version on macOS or iOS
    On macOS, open Safari and go to Safari > About Safari. On iOS, go to Settings > Safari > About. Note the version number displayed.
    Affected if The version shown is earlier than 11.1 (for example, 11.0.x or any 10.x version)
  2. Check WebKit version in Safari
    In Safari, enable the Develop menu (Preferences > Advanced > Show Develop menu), then select Develop > WebKit Version. Alternatively, visit about:webkit in the browser address bar.
    Affected if The WebKit version number is lower than the version bundled with Safari 11.1 (typically earlier than WebKit 605.1.x)
  3. Identify Ubuntu Linux version
    Run the command: cat /etc/lsb-release or hostnamectl. Look for the DISTRIB_RELEASE or VERSION_ID field.
    Affected if The version reported is 16.04 or 17.10 exactly
  4. Check WebKitgtk version on Ubuntu
    Run: dpkg -l | grep webkit or apt list --installed | grep webkit. Record the version number shown.
    Affected if The installed webkitgtk version is lower than 2.20.4 (for example, 2.20.3 or earlier)
  5. Verify WebKitgtk library file version
    Check the shared library directly: ls -la /usr/lib/x86_64-linux-gnu/libwebkit2* or find /usr -name "libwebkit*" -type f 2>/dev/null. Use dpkg -S on the library file to get its version.
    Affected if The library version returned by dpkg -s or dpkg -S is less than 2.20.4

You are affected if Safari is earlier than version 11.1, or if running Ubuntu 16.04/17.10 with webkitgtk installed at a version lower than 2.20.4.

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 2.20.4 / 11.1 or later
Fixed in 2.20.411.1
Interim mitigation

Upgrade Safari to version 11.1 or later to remediate this vulnerability. Organizations should deploy the update via their device management or patch management infrastructure.

Fix this in Safari Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2018-4133 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