CVE-2021-1857: Apple iCloud

Medium severity, CVSS 6.5. EPSS: 1.2% chance of exploitation in the next 30 days.

A memory initialization issue was addressed with improved memory handling. This issue is fixed in iTunes 12.11.3 for Windows, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave, iCloud for Windows 12.3, macOS Big Sur 11.3, watchOS 7.4, tvOS 14.5, iOS 14.5 and iPadOS 14.5. Processing maliciously crafted web content may disclose sensitive user information.

Affected products

• Apple iCloud: before 12.3 (fixed in 12.3)
• Apple iPadOS: before 14.5 (fixed in 14.5)
• Apple iPhone OS: before 14.5 (fixed in 14.5)
• Apple iTunes: before 12.11.3 (fixed in 12.11.3)
• Apple Mac OS X: version 10.14 only; version 10.14.0 only; version 10.14.1 only; version 10.14.2 only; version 10.14.3 only; version 10.14.4 only; …
• Apple macOS: from 11.0, before 11.3 (fixed in 11.3)
• Apple tvOS: before 14.5 (fixed in 14.5)
• Apple watchOS: before 7.4 (fixed in 7.4)

Published 2021-09-08. Last modified 2026-06-17.