CVE-2023-41991
MediumExploitedPublic exploitA certificate validation issue was addressed.
Published Sep 22, 2023 · Updated Nov 4, 2025 · Also known as TR-23-0551
Key Facts
Patch immediately- CVE-2023-41991 is a medium-severity vulnerability (CVSS 5.5 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 Sep 12, 2023. Public exploit code is available.
- EPSS estimates a 13% probability of exploitation in the next 30 days.
- Fixed versions are available, including Ipados 16.7, Iphone OS 16.7, macOS 13.6.
- 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:N/I:H/A:N
EPSS (30-day exploit likelihood)
13%
Higher than 96.3% 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-2023-41991 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
A certificate validation issue was addressed. This issue is fixed in macOS Ventura 13.6, iOS 16.7 and iPadOS 16.7. A malicious app may be able to bypass signature validation. Apple is aware of a report that this issue may have been actively exploited against versions of iOS before iOS 16.7.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Sep 25, 2023 | Oct 16, 2023 | Not reported |
| Industry KEV feed | Sep 12, 2023 | Oct 16, 2023 | Not reported |
| CIRCL KEV | Sep 25, 2023 | Oct 16, 2023 | Not reported |
| ENISA EUVD | Sep 25, 2023 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected Products
7 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IpadosApple | 17.0 | 16.7 |
| Iphone OSApple | 17.0 | 16.7 |
| macOSApple | >= unspecified | 13.6 |
| iOS and iPadOS | >= unspecified | 16.7 |
Patched Releases
Ipados
16.7
Iphone OS
16.7
macOS
13.6
iOS and iPadOS
16.7
Timeline
Added to Industry KEV feed
Sep 12, 2023
Publicly disclosed
Sep 22, 2023
Added to CISA KEV
Sep 25, 2023
Added to CIRCL KEV
Sep 25, 2023
Added to ENISA EUVD
Sep 25, 2023
Last updated
Nov 4, 2025
Weakness Type
- CWE-295 Improper Certificate Validation
References
- advisoryhttps://support.apple.com/en-us/HT213927
- advisoryhttps://support.apple.com/en-us/HT213931
- advisoryVulnCheck exploitation report
- advisoryVulnCheck exploitation report
- advisoryhttps://www.macworld.com/article/2079324/ios-17-update-iphone-15-bug-fixes-security-updates.html
FAQ
Common Questions.
A certificate validation issue was addressed.
Affected: Ipados (Apple) versions 17.0; Iphone OS (Apple) versions 17.0; 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 Sep 12, 2023.
Yes. It was added on Sep 25, 2023 with a federal remediation due date of Oct 16, 2023.
Public exploit code is available.
Fixed versions are available, including Ipados 16.7, Iphone OS 16.7, macOS 13.6.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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