CVE-2020-27950
MediumExploitedPublic exploitA memory initialization issue was addressed.
Published Mar 29, 2021 · Updated Oct 21, 2025
Key Facts
Patch immediately- CVE-2020-27950 is a medium-severity vulnerability (CVSS 5.5 v3.1) affecting Ipados (Apple), Iphone OS (Apple), macOS (Apple) and 2 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 29, 2020. Public exploit code is available.
- EPSS estimates a 17% probability of exploitation in the next 30 days.
- Fixed versions are available, including Ipados 14.2, Iphone OS 12.4.9, macOS 10.15.7.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
5.5
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS (30-day exploit likelihood)
17%
Higher than 96.9% 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-2020-27950 brief as a PDF
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Description
A memory initialization issue was addressed. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 12.4.9, watchOS 6.2.9, Security Update 2020-006 High Sierra, Security Update 2020-006 Mojave, iOS 14.2 and iPadOS 14.2, watchOS 5.3.9, macOS Catalina 10.15.7 Supplemental Update, macOS Catalina 10.15.7 Update. A malicious application may be able to disclose kernel memory.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Nov 3, 2021 | May 3, 2022 | Not reported |
| Industry KEV feed | Oct 29, 2020 | May 3, 2022 | Not reported |
| CIRCL KEV | Nov 3, 2021 | May 3, 2022 | Not reported |
| ENISA EUVD | Nov 3, 2021 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
7 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IpadosApple | See advisory | 14.2 |
| Iphone OSApple | See advisory | 12.4.9 |
| macOSApple | >= unspecified | 10.15.7 |
| watchOSApple | >= unspecified | 5.3.9 |
| iOS and iPadOS | >= unspecified | 14.2 |
Patched Releases
Ipados
14.2
Iphone OS
12.4.9
macOS
10.15.7, 10.15, 11.0, 12.4, 2020, 5.3, 6.2
watchOS
5.3.9, 7.1
iOS and iPadOS
14.2
Timeline
Added to Industry KEV feed
Oct 29, 2020
Publicly disclosed
Mar 29, 2021
Added to CISA KEV
Nov 3, 2021
Added to CIRCL KEV
Nov 3, 2021
Added to ENISA EUVD
Nov 3, 2021
Last updated
Oct 21, 2025
Weakness Type
- CWE-665 Improper Initialization
References
- advisoryhttp://feedproxy.google.com/~r/TheHackersNews/~3/xR_aHfkOkh4/apple-issues-urgent-patch-update-for.html
- advisoryhttp://packetstormsecurity.com/files/161296/XNU-Kernel-Mach-Message-Trailers-Memory-Disclosure.html
- advisory20201215 APPLE-SA-2020-12-14-4 Additional information for APPLE-SA-2020-11-13-1 macOS Big Sur 11.0.1
- advisoryhttps://isc.sans.edu/
- advisoryhttps://isc.sans.edu/diary/rss/27250
FAQ
Common Questions.
A memory initialization issue was addressed.
Affected: Ipados (Apple); Iphone OS (Apple); macOS (Apple) versions >= unspecified, 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 Oct 29, 2020.
Yes. It was added on Nov 3, 2021 with a federal remediation due date of May 3, 2022.
Public exploit code is available.
Fixed versions are available, including Ipados 14.2, Iphone OS 12.4.9, macOS 10.15.7.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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