CVE-2021-30900
HighExploitedPublic exploitAn out-of-bounds write issue was addressed with improved bounds checking.
Published Aug 24, 2021 · Updated Oct 23, 2025
Key Facts
Patch immediately- CVE-2021-30900 is a high-severity vulnerability (CVSS 7.8 v3.1) affecting Ipados (Apple), Iphone OS (Apple), Macos (Apple) and 1 more product.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 29, 2023. Public exploit code is available.
- EPSS estimates a 5.2% probability of exploitation in the next 30 days.
- Fixed versions are available, including Ipados 14.8.1, Iphone OS 14.8.1, Macos 11.6.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.8
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
5.2%
Higher than 92.3% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-30900 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 30, 2023 | Apr 20, 2023 | Not reported |
| Industry KEV feed | Mar 29, 2023 | Apr 20, 2023 | Not reported |
| CIRCL KEV | Mar 30, 2023 | Apr 20, 2023 | Not reported |
| ENISA EUVD | Mar 30, 2023 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
6 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IpadosApple | 15.0 | 14.8.1 |
| Iphone OSApple | 15.0 | 14.8.1 |
| MacosApple | See advisory | 11.6.1 |
| iOS and iPadOS | >= unspecified | 15.1 |
Patched Releases
Ipados
14.8.1
Iphone OS
14.8.1
Macos
11.6.1
iOS and iPadOS
14.8, 15.1
Timeline
Publicly disclosed
Aug 24, 2021
Added to Industry KEV feed
Mar 29, 2023
Added to CISA KEV
Mar 30, 2023
Added to CIRCL KEV
Mar 30, 2023
Added to ENISA EUVD
Mar 30, 2023
Last updated
Oct 23, 2025
Weakness Type
- CWE-787 Out-of-bounds Write
References
- advisoryhttps://support.apple.com/en-us/HT212867
- advisoryhttps://support.apple.com/en-us/HT212868
- advisoryhttps://support.apple.com/kb/HT212872
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
An out-of-bounds write issue was addressed with improved bounds checking.
Affected: Ipados (Apple) versions 15.0; Iphone OS (Apple) versions 15.0; Macos (Apple), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 29, 2023.
Yes. It was added on Mar 30, 2023 with a federal remediation due date of Apr 20, 2023.
Public exploit code is available.
Fixed versions are available, including Ipados 14.8.1, Iphone OS 14.8.1, Macos 11.6.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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