What’s Vulnerable › Vulnerabilities

CVE-2021-1791

• Severity: medium (CVSS 5.5 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: 2021-04-02 · updated 2026-06-17
• Weakness: CWE-125

Description

An out-of-bounds read issue existed that led to the disclosure of kernel memory. This was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, watchOS 7.3, tvOS 14.4, iOS 14.4 and iPadOS 14.4. A malicious application may be able to disclose kernel memory.

Affected products

• Apple iPadOS: before 14.4 — fixed in 14.4
• Apple Iphone Os: before 14.4 — fixed in 14.4
• macOS: from 10.14 before 10.14.6; from 10.15 before 10.15.7; 10.14.6, 10.14.6-security_update_2019-004, 10.14.6-security_update_2019-005, 10.14.6-security_update_2019-006, 10.14.6-security_update_2019-007, 10.14.6-security_update_2020-001 (+10) — fixed in 10.14.6, 10.15.7
• Apple macOS: from 11.0 before 11.2 — fixed in 11.2
• Apple tvOS: before 14.4 — fixed in 14.4
• Apple watchOS: before 7.3 — fixed in 7.3

How to fix

Upgrade to a fixed version: Apple iPadOS 14.4; Apple Iphone Os 14.4; macOS 10.14.6, 10.15.7; Apple macOS 11.2; Apple tvOS 14.4; Apple watchOS 7.3. Check the vendor advisory for mitigations.

References

• https://support.apple.com/en-us/HT212146
• https://support.apple.com/en-us/HT212147
• https://support.apple.com/en-us/HT212148
• https://support.apple.com/en-us/HT212149
• https://support.apple.com/en-us/HT212146
• https://support.apple.com/en-us/HT212147
• https://support.apple.com/en-us/HT212148
• https://support.apple.com/en-us/HT212149

Get alerted when CVE-2021-1791 or the next vulnerability affects your stack