What’s Vulnerable › Vulnerabilities

CVE-2018-4377

• Severity: medium (CVSS 6.1 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-04-03 · updated 2026-06-17
• Weakness: CWE-79

Description

A cross-site scripting issue existed in Safari. This issue was addressed with improved URL validation. This issue affected versions prior to iOS 12.1, watchOS 5.1, Safari 12.0.1, iTunes 12.9.1, iCloud for Windows 7.8.

Affected products

• Apple iCloud for Windows: before 7.8 — fixed in 7.8
• Apple Iphone Os: before 12.1 — fixed in 12.1
• Apple iTunes for Windows: before 12.9.1 — fixed in 12.9.1
• Apple Safari: before 12.0.1 — fixed in 12.0.1
• Apple watchOS: before 5.1 — fixed in 5.1

How to fix

Upgrade to a fixed version: Apple iCloud for Windows 7.8; Apple Iphone Os 12.1; Apple iTunes for Windows 12.9.1; Apple Safari 12.0.1; Apple watchOS 5.1. Check the vendor advisory for mitigations.

References

• https://support.apple.com/kb/HT209192
• https://support.apple.com/kb/HT209195
• https://support.apple.com/kb/HT209196
• https://support.apple.com/kb/HT209197
• https://support.apple.com/kb/HT209198
• https://support.apple.com/kb/HT209192
• https://support.apple.com/kb/HT209195
• https://support.apple.com/kb/HT209196
• https://support.apple.com/kb/HT209197
• https://support.apple.com/kb/HT209198

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