What’s Vulnerable › Vulnerabilities

CVE-2021-1857

• Severity: medium (CVSS 6.5 v3.1)
• 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: 2021-09-08 · updated 2026-06-17
• Weakness: CWE-665

Description

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 for Windows: 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 for Windows: before 12.11.3 — fixed in 12.11.3
• macOS: 10.14, 10.14.0, 10.14.1, 10.14.2, 10.14.3, 10.14.4 (+32)
• 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

How to fix

Upgrade to a fixed version: Apple iCloud for Windows 12.3; Apple iPadOS 14.5; Apple Iphone Os 14.5; Apple iTunes for Windows 12.11.3; Apple macOS 11.3; Apple tvOS 14.5; Apple watchOS 7.4. Check the vendor advisory for mitigations.

References

• https://support.apple.com/en-us/HT212317
• https://support.apple.com/en-us/HT212319
• https://support.apple.com/en-us/HT212321
• https://support.apple.com/en-us/HT212323
• https://support.apple.com/en-us/HT212324
• https://support.apple.com/en-us/HT212325
• https://support.apple.com/en-us/HT212326
• https://support.apple.com/en-us/HT212327
• https://support.apple.com/en-us/HT212317
• https://support.apple.com/en-us/HT212319
• https://support.apple.com/en-us/HT212321
• https://support.apple.com/en-us/HT212323

Get alerted when CVE-2021-1857 or the next vulnerability affects your stack