CVE-2021-1811

CVE-2021-1811 is a medium-severity vulnerability in Apple Icloud with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

• Severity: Medium (CVSS 3.x base score 6.5)
• CVSS v2: 4.3
• EPSS exploit prediction: 2% (74th percentile)
• Actively exploited: Not listed in CISA KEV
• Affected product: Apple Icloud
• Published: 2021-09-08
• Last modified: 2026-06-17

Description

A logic issue was addressed with improved state management. This issue is fixed in iTunes 12.11.3 for Windows, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave, iCloud for Windows 12.3, macOS Big Sur 11.3, watchOS 7.4, tvOS 14.5, iOS 14.5 and iPadOS 14.5. Processing a maliciously crafted font may result in the disclosure of process memory.

Frequently asked questions

What is CVE-2021-1811?

A logic issue was addressed with improved state management. This issue is fixed in iTunes 12.11.3 for Windows, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave, iCloud for Windows 12.3, macOS Big Sur 11.3, watchOS 7.4, tvOS 14.5, iOS 14.5 and iPadOS 14.5. Processing a maliciously crafted font may result in the disclosure of process memory.

How severe is CVE-2021-1811?

CVE-2021-1811 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-1811 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1811?

CVE-2021-1811 primarily affects Apple Icloud. In total, 35 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1811?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-1811 published?

CVE-2021-1811 was published on 2021-09-08 and last updated on 2026-06-17.

References

• https://support.apple.com/en-us/HT212317
• https://support.apple.com/en-us/HT212319
• https://support.apple.com/en-us/HT212321
• https://support.apple.com/en-us/HT212323
• https://support.apple.com/en-us/HT212324
• https://support.apple.com/en-us/HT212325
• https://support.apple.com/en-us/HT212326
• https://support.apple.com/en-us/HT212327

Affected products (35)

• cpe:2.3:a:apple:icloud:*:*:*:*:*:windows:*:*
• cpe:2.3:a:apple:itunes:*:*:*:*:*:windows:*:*
• cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
• cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:-:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-001:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-002:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-004:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-005:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-006:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-007:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-001:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-002:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-003:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-004:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-005:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-006:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-007:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-001:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-002:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:supplemental_update:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:supplemental_update_2:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.15.6:-:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.15.6:supplemental_update:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.15.7:-:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-001:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-005:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-007:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-001:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.15.7:supplemental_update:*:*:*:*:*:*
• cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
• cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
• cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

More vulnerabilities in Apple Icloud

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• CVE-2020-9895 — Critical (CVSS 9.8): A use after free issue was addressed with improved memory management. This issue is fixed in iOS 13.6 and iPadOS 13.6,…
• CVE-2020-9850 — Critical (CVSS 9.8): A logic issue was addressed with improved restrictions. This issue is fixed in iOS 13.5 and iPadOS 13.5, tvOS 13.4.5,…
• CVE-2020-3911 — Critical (CVSS 9.8): A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 13.4 and iPadOS 13.4, macOS…

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