Apple Multiple products Use-After-Free
CVE-2023-43000 is a high-severity use after free vulnerability in macOS from Apple, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 13.5 as the first without the flaw, so updating macOS to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on March 5, 2026, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update macOS to 13.5 or a later version.
- Update iOS and iPadOS to 16.6 or 15.8.7, whichever matches your release line, or a later version.
- Update Safari to 16.6 or a later version.
- CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apple | macOS | before 13.5 | 13.5 |
| Apple | iOS and iPadOS | before 16.6; before 15.8.7 | 16.6, 15.8.7 |
| Apple | Safari | before 16.6 | 16.6 |
| Apple | iPadOS | before 15.8.7; 16.0 up to, but not including, 16.6 | 15.8.7, 16.6 |
| Apple | Iphone OS | before 15.8.7; 16.0 up to, but not including, 16.6 | 15.8.7, 16.6 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 3.1 | 8.8 | High | CISA (ADP) |
Official description
A use-after-free issue was addressed with improved memory management. This issue is fixed in macOS Ventura 13.5, iOS 16.6 and iPadOS 16.6, Safari 16.6, iOS 15.8.7 and iPadOS 15.8.7. Processing maliciously crafted web content may lead to memory corruption.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
- support.apple.com/en-us/120324Release Notes
- support.apple.com/en-us/120331Release Notes
- support.apple.com/en-us/120338Release Notes
- support.apple.com/en-us/126632Release Notes
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-43000US Government Resource
Technical write-ups (may include proof of concept)
- cloud.google.com/blog/topics/threat-intelligence/coruna-powerful-ios-exploit-kitExploit, Third Party Advisory
Other vulnerabilities in macOS
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Use After Free vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.3 High severity
- 7.3 High severity
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