What’s Vulnerable › Vulnerabilities

CVE-2021-30851

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.4% 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-787

Description

A memory corruption vulnerability was addressed with improved locking. This issue is fixed in Safari 15, tvOS 15, watchOS 8, iOS 15 and iPadOS 15. Processing maliciously crafted web content may lead to code execution.

Affected products

• Apple iPadOS: before 15.0 — fixed in 15.0
• Apple Iphone Os: before 15.0 — fixed in 15.0
• Apple macOS: before 12.0.1; 12.0.1 — fixed in 12.0.1
• Apple Safari: before 15.0 — fixed in 15.0
• Apple tvOS: before 15.0 — fixed in 15.0
• Apple watchOS: before 8.0 — fixed in 8.0
• Debian Linux: 10.0, 11.0
• Fedoraproject Fedora: 33, 34

How to fix

Upgrade to a fixed version: Apple iPadOS 15.0; Apple Iphone Os 15.0; Apple macOS 12.0.1; Apple Safari 15.0; Apple tvOS 15.0; Apple watchOS 8.0. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2021/10/31/1
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H6MGXCX7P5AHWOQ6IRT477UKT7IS4DAD/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ON5SDVVPVPCAGFPW2GHYATZVZYLPW2L4/
• https://support.apple.com/en-us/HT212814
• https://support.apple.com/en-us/HT212815
• https://support.apple.com/en-us/HT212816
• https://support.apple.com/en-us/HT212819
• https://support.apple.com/kb/HT212869
• https://www.debian.org/security/2021/dsa-4995
• https://www.debian.org/security/2021/dsa-4996
• http://www.openwall.com/lists/oss-security/2021/10/31/1
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H6MGXCX7P5AHWOQ6IRT477UKT7IS4DAD/

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