CyberSecBulletin
CVE-2023-28201NVD status: Modified

macOS: Concurrent Execution using Shared Resource with Improper Synchronization

CVE-2023-28201 is a critical-severity concurrent execution using shared resource with improper synchronization vulnerability in macOS from Apple, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 13.3 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 1.17% chance of exploitation within 30 days, higher than 68% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update macOS to 13.3 or a later version.
  2. Update Safari to 16.4 or a later version.
  3. Update iOS and iPadOS to 16.4 or 15.7, whichever matches your release line, or a later version.
  4. Read the advisory on support.apple.com for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
ApplemacOSbefore 13.313.3
AppleSafaribefore 16.416.4
AppleiOS and iPadOSbefore 16.4; before 15.716.4, 15.7
AppletvOSbefore 16.416.4
AppleiPadOSbefore 15.7.4; 16.0 up to, but not including, 16.415.7.4, 16.4
AppleIphone OSbefore 15.7.4; 16.0 up to, but not including, 16.415.7.4, 16.4

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
NoneNo action by a victim is required.
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:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalNVD
CVSS 3.19.8CriticalCISA (ADP)

Official description

This issue was addressed with improved state management. This issue is fixed in macOS Ventura 13.3, Safari 16.4, iOS 16.4 and iPadOS 16.4, iOS 15.7.4 and iPadOS 15.7.4, tvOS 16.4. A remote user may be able to cause unexpected app termination or arbitrary code execution.

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).

More Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities (CWE-362)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in macOS

All macOS vulnerabilities

Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities

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