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TI-2021-01560 Aliases CVE-2021-1855GHSA-x2pr-2f5w-h2hj

Apple macOS: A malicious website may be able to force unnecessary network connections to…

Priority LOW 30Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3. A malicious website may be able to force unnecessary network connections to fetch its favicon.

Why it matters now

EPSS 0.00789 56th percentileScored 2026-11-07
Fix Fixed macOS (Apple): 11.3

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
ApplemacOSbefore 11.311.3Patch availableCNA
  • macOS VendorApple Affected before 11.3 Fixed in 11.3 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*11.0 to before 11.3VulnerableApple
  • cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* Versions 11.0 to before 11.3 Vulnerable ·Apple

Remediation

  • Fix · CNA macOS (Apple) Fixed in 11.3

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Apple macOS 11.3

    62 records Highest priority Priority CRITICAL 3 CRITICAL, 1 HIGH, 9 MEDIUM, 49 LOW

    Other records, highest priority first

    • TI-2021-11050 Out-of-bounds write in Apple macOSPriority CRITICAL 97
    • TI-2021-11048 Integer overflow in Apple macOSPriority CRITICAL 97
    • TI-2021-11046 Use after free in Apple iOS and iPadOSPriority CRITICAL 97
    Show all 62 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-1855
  2. 2026-10-03 Alias added: GHSA-x2pr-2f5w-h2hj

References

Advisory 1

  • TI-2026-46583 Improper authentication in Apple macOS KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-28008 Out-of-bounds write in Apple iOS and iPadOS KEVCVSS 3.1CRITICAL 10.0
  • TI-2025-22441 Apple iOS and iPadOS: An attacker with arbitrary read and write capability may be able to… KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-22440 Memory corruption in Apple iOS and iPadOS KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-17951 Out-of-bounds write in Apple Safari KEVCVSS 3.1CRITICAL 10.0
  • TI-2025-17847 Use after free in Apple iOS and iPadOS KEVCVSS 3.1CRITICAL 10.0
See all 3490 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences