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TI-2021-01528 Aliases CVE-2021-1817GHSA-wm9j-fw55-hv9g

Out-of-bounds write in Apple iOS and iPadOS

Priority MEDIUM 42CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 3 fixed, 2 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.

Summary

A memory corruption issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5. Processing maliciously crafted web content may lead to arbitrary code execution.

Why it matters now

EPSS 0.01939 80th percentileScored 2026-11-07
Fix Partial iOS and iPadOS (Apple): 14.5tvOS (Apple): 14.5+2 more productsRed Hat: 2 advisoriesRed Hat: 3 fixed, 2 without a fix

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
AppleiOS and iPadOSbefore 14.514.5Patch availableCNA
AppletvOSbefore 14.514.5Patch availableCNA
ApplewatchOSbefore 7.47.4Patch availableCNA
ApplemacOSbefore 11.311.3Patch availableCNA
  • iOS and iPadOS VendorApple Affected before 14.5 Fixed in 14.5 Patch available CNA
  • tvOS VendorApple Affected before 14.5 Fixed in 14.5 Patch available CNA
  • watchOS VendorApple Affected before 7.4 Fixed in 7.4 Patch available CNA
  • macOS VendorApple Affected before 11.3 Fixed in 11.3 Patch available CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*before 14.5VulnerableApple
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*before 14.5VulnerableApple
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*11.0 to before 11.3VulnerableApple
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*before 14.5VulnerableApple
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*before 7.4VulnerableApple
  • cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:* Versions before 14.5 Vulnerable ·Apple
  • cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:* Versions before 14.5 Vulnerable ·Apple
  • cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* Versions 11.0 to before 11.3 Vulnerable ·Apple
  • cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:* Versions before 14.5 Vulnerable ·Apple
  • cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:* Versions before 7.4 Vulnerable ·Apple

Remediation

  • Fix · CNA iOS and iPadOS (Apple) Fixed in 14.5
  • Fix · CNA tvOS (Apple) Fixed in 14.5
  • Fix · CNA watchOS (Apple) Fixed in 7.4
  • Fix · CNA macOS (Apple) Fixed in 11.3

Red Hat 2 advisories

  • RHSA-2025:10364 Released 2025-07-07 · Red Hat rating Important
    webkitgtk4 security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) webkitgtk4-2.48.3-2.el7_9, webkitgtk4-devel-2.48.3-2.el7_9, webkitgtk4-jsc-2.48.3-2.el7_9 +1
    • Red Hat Enterprise Linux Server Optional (v. 7 ELS) webkitgtk4-devel-2.48.3-2.el7_9, webkitgtk4-doc-2.48.3-2.el7_9, webkitgtk4-jsc-devel-2.48.3-2.el7_9
  • RHSA-2021:1586 Released 2021-05-18 · Red Hat rating Moderate
    GNOME security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder (v. 8) glib2-doc-2.56.4-9.el8, glib2-static-2.56.4-9.el8
    • Red Hat Enterprise Linux AppStream (v. 8) gdm-1:3.28.3-39.el8, webkit2gtk3-2.30.4-1.el8, webkit2gtk3-devel-2.30.4-1.el8 +2
    • Red Hat Enterprise Linux BaseOS (v. 8) glib2-2.56.4-9.el8, glib2-devel-2.56.4-9.el8, glib2-fam-2.56.4-9.el8 +1

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 →
  • Release ·

    Apple iOS and iPadOS 14.5

    60 records Highest priority Priority CRITICAL 1 CRITICAL, 7 MEDIUM, 52 LOW

    Other records, highest priority first

    • TI-2021-11046 Use after free in Apple iOS and iPadOSPriority CRITICAL 97
    • TI-2021-01483 Memory corruption in Apple iOS and iPadOSPriority MEDIUM 47
    • TI-2021-01568 Use after free in Apple iOS and iPadOSPriority MEDIUM 46
    Show all 60 records →
Show 2 more groups
  • Release ·

    Apple watchOS 7.4

    43 records Highest priority Priority CRITICAL 1 CRITICAL, 5 MEDIUM, 37 LOW

    Other records, highest priority first

    • TI-2021-11046 Use after free in Apple iOS and iPadOSPriority CRITICAL 97
    • TI-2021-01483 Memory corruption in Apple iOS and iPadOSPriority MEDIUM 47
    • TI-2021-01568 Use after free in Apple iOS and iPadOSPriority MEDIUM 46
    Show all 43 records →
  • Release ·

    Apple tvOS 14.5

    39 records Highest priority Priority CRITICAL 1 CRITICAL, 5 MEDIUM, 33 LOW

    Other records, highest priority first

    • TI-2021-11046 Use after free in Apple iOS and iPadOSPriority CRITICAL 97
    • TI-2021-01483 Memory corruption in Apple iOS and iPadOSPriority MEDIUM 47
    • TI-2021-01568 Use after free in Apple iOS and iPadOSPriority MEDIUM 46
    Show all 39 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2021:1586
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2025:10364
Red Hat Enterprise Linux Server Optional (v. 7 ELS)Fixed RHSA-2025:10364
Not affected: 4 products
  • Red Hat CodeReady Linux Builder (v. 8)
  • Red Hat Enterprise Linux 9
  • Red Hat Enterprise Linux AppStream (v. 8)
  • Red Hat Enterprise Linux BaseOS (v. 8)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-1817
  2. 2026-10-03 Alias added: GHSA-wm9j-fw55-hv9g

References

Advisory 4

  • 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
  • TI-2022-06854 Out-of-bounds write in Apple iOS and iPadOS KEVCVSS 3.1CRITICAL 9.8
See all 2382 →

Sources

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