macOS: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2022-42864 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in macOS from Apple, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 11.7 as the first without the flaw, so updating macOS to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.9% chance of exploitation within 30 days, higher than 60% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update macOS to 11.7 or a later version.
- Update tvOS to 16.2 or 13.1 or 12.6 or 15.7, whichever matches your release line, or a later version.
- Update watchOS to 9.2 or a later version.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
- 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 11.7 | 11.7 |
| Apple | tvOS | before 16.2; before 13.1; before 12.6; before 15.7 | 16.2, 13.1, 12.6, 15.7 |
| Apple | watchOS | before 9.2 | 9.2 |
| Apple | iPadOS | before 15.7.2; 16.0 up to, but not including, 16.2 | 15.7.2, 16.2 |
| Apple | Iphone OS | before 15.7.2; 16.0 up to, but not including, 16.2 | 15.7.2, 16.2 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- 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:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.0 | High | NVD |
| CVSS 3.1 | 7.0 | High | CISA (ADP) |
Official description
A race condition was addressed with improved state handling. This issue is fixed in tvOS 16.2, macOS Monterey 12.6.2, macOS Ventura 13.1, macOS Big Sur 11.7.2, iOS 15.7.2 and iPadOS 15.7.2, iOS 16.2 and iPadOS 16.2, watchOS 9.2. An app may be able to execute arbitrary code with kernel privileges.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
How developers prevent this class of flaw
- In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
- Use thread-safe capabilities such as the data access abstraction in Spring.
- Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- support.apple.com/en-us/HT213530Release Notes
- support.apple.com/en-us/HT213531Release Notes
- support.apple.com/en-us/HT213532Release Notes
- support.apple.com/en-us/HT213533Release Notes
- support.apple.com/en-us/HT213534Release Notes
- support.apple.com/en-us/HT213535Release Notes
- support.apple.com/en-us/HT213536Release Notes
Third-party and government advisories
- seclists.org/fulldisclosure/2022/Dec/20Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2022/Dec/21Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2022/Dec/23Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2022/Dec/24Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2022/Dec/25Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2022/Dec/26Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2022/Dec/27Mailing List, Third Party Advisory
Other vulnerabilities in macOS
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Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
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