CVE-2021-1883: Apple iPadOS

Medium severity, CVSS 5.5. EPSS: 2% chance of exploitation in the next 30 days.

This issue was addressed with improved checks. This issue is fixed in Security Update 2021-004 Mojave, iOS 14.5 and iPadOS 14.5, watchOS 7.4, Security Update 2021-003 Catalina, tvOS 14.5, macOS Big Sur 11.3. Processing maliciously crafted server messages may lead to heap corruption.

Affected products

• Apple iPadOS: before 14.5 (fixed in 14.5)
• Apple iPhone OS: before 14.5 (fixed in 14.5)
• Apple Mac OS X: from 10.14, up to and including 10.14.5; from 10.15, up to and including 10.15.5; version 10.14.6 only; version 10.15.6 only; version 10.15.7 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.