What’s Vulnerable › Vulnerabilities

CVE-2021-30977

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% 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-120

Description

A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Monterey 12.1, Security Update 2021-008 Catalina, macOS Big Sur 11.6.2. A malicious application may be able to execute arbitrary code with kernel privileges.

Affected products

• macOS: from 10.15 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 (+4) — fixed in 10.15.7
• Apple macOS: from 11.0 before 11.6.2; from 12.0 before 12.3 — fixed in 11.6.2, 12.3

How to fix

Upgrade to a fixed version: macOS 10.15.7; Apple macOS 11.6.2, 12.3. Check the vendor advisory for mitigations.

References

• https://support.apple.com/en-us/HT212978
• https://support.apple.com/en-us/HT212979
• https://support.apple.com/en-us/HT212981
• https://support.apple.com/kb/HT213183
• https://support.apple.com/en-us/HT212978
• https://support.apple.com/en-us/HT212979
• https://support.apple.com/en-us/HT212981
• https://support.apple.com/kb/HT213183

Get alerted when CVE-2021-30977 or the next vulnerability affects your stack