What’s Vulnerable › Vulnerabilities

CVE-2021-30857

• Severity: high (CVSS 7.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-08-24 · updated 2026-06-17
• Weakness: CWE-362

Description

A race condition was addressed with improved locking. This issue is fixed in Security Update 2021-005 Catalina, iOS 14.8 and iPadOS 14.8, tvOS 15, iOS 15 and iPadOS 15, watchOS 8, macOS Big Sur 11.6. A malicious application may be able to execute arbitrary code with kernel privileges.

Affected products

• Apple iPadOS: before 15.0 — fixed in 15.0
• Apple Iphone Os: before 15.0 — fixed in 15.0
• macOS: before 10.15.7; 10.15.7, 10.15.7-security_update_2020-001, 10.15.7-security_update_2021-001, 10.15.7-security_update_2021-002, 10.15.7-security_update_2021-003, 10.15.7-security_update_2021-004 (+1) — fixed in 10.15.7
• Apple macOS: from 11.0 before 11.6 — fixed in 11.6
• Apple tvOS: before 15.0 — fixed in 15.0
• Apple watchOS: before 8.0 — fixed in 8.0

How to fix

Upgrade to a fixed version: Apple iPadOS 15.0; Apple Iphone Os 15.0; macOS 10.15.7; Apple macOS 11.6; Apple tvOS 15.0; Apple watchOS 8.0. Check the vendor advisory for mitigations.

References

• https://support.apple.com/en-us/HT212804
• https://support.apple.com/en-us/HT212805
• https://support.apple.com/en-us/HT212807
• https://support.apple.com/en-us/HT212814
• https://support.apple.com/en-us/HT212815
• https://support.apple.com/en-us/HT212819
• https://support.apple.com/en-us/HT212804
• https://support.apple.com/en-us/HT212805
• https://support.apple.com/en-us/HT212807
• https://support.apple.com/en-us/HT212814
• https://support.apple.com/en-us/HT212815
• https://support.apple.com/en-us/HT212819

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