CVE-2021-30900 Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability
Apple GPU drivers, included in iOS, iPadOS, and macOS, contain an out-of-bounds write vulnerability that may allow a malicious application to execute code with kernel privileges.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 30 Mar 2023.
- Rated High severity (CVSS 7.8, scored by CISA).
- It has been in the catalogue for 1,317 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 14.8.1 and iPadOS 14.8.1, iOS 15.1 and iPadOS 15.1. A malicious application may be able to execute arbitrary code with kernel privileges.
Affected Versions
| Product | Versions |
|---|---|
| Apple iOS and iPadOS | unspecified to before 15.1 |
| Apple iOS and iPadOS | unspecified to before 14.8 |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Apple iOS, iPadOS, and macOS. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
- 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
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