What’s Vulnerable › Vulnerabilities

CVE-2021-30821

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-10-28 · updated 2026-06-17

Description

A memory corruption issue was addressed with improved memory handling. This issue is fixed in macOS Monterey 12.0.1, Security Update 2021-007 Catalina, macOS Big Sur 11.6.1. A malicious application may be able to execute arbitrary code with kernel privileges.

Affected products

• 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 (+3) — fixed in 10.15.7
• Apple macOS: from 11.0 before 11.6.1; from 12.0.0 before 12.0.1 — fixed in 11.6.1, 12.0.1

How to fix

Upgrade to a fixed version: macOS 10.15.7; Apple macOS 11.6.1, 12.0.1. Check the vendor advisory for mitigations.

References

• https://support.apple.com/en-us/HT212869
• https://support.apple.com/en-us/HT212871
• https://support.apple.com/en-us/HT212872
• https://support.apple.com/en-us/HT212869
• https://support.apple.com/en-us/HT212871
• https://support.apple.com/en-us/HT212872

Get alerted when CVE-2021-30821 or the next vulnerability affects your stack