iOS and iPadOS: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2024-40815 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in iOS and iPadOS from Apple, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 17.6 as the first without the flaw, so updating iOS and iPadOS to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.09% chance of exploitation within 30 days, higher than 66% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update iOS and iPadOS to 17.6 or a later version.
- Update macOS to 13.6.8 or 14.6, whichever matches your release line, or a later version.
- Update tvOS to 17.6 or a later version.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apple | iOS and iPadOS | before 17.6 | 17.6 |
| Apple | macOS | before 13.6.8; before 14.6; 13.0 up to, but not including, 13.6.8; 14.0 up to, but not including, 14.6 | 13.6.8, 14.6 |
| Apple | tvOS | before 17.6 | 17.6 |
| Apple | watchOS | before 10.6 | 10.6 |
| Apple | iphone_os | before 17.6 | 17.6 |
| Apple | ipad_os | before 17.6 | 17.6 |
| Apple | iPadOS | before 17.6 | 17.6 |
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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- 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:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 7.5 | High | CISA (ADP) |
Official description
A race condition was addressed with additional validation. This issue is fixed in iOS 17.6 and iPadOS 17.6, macOS Sonoma 14.6, macOS Ventura 13.6.8, tvOS 17.6, watchOS 10.6. A malicious attacker with arbitrary read and write capability may be able to bypass Pointer Authentication.
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/HT214117Release Notes
- support.apple.com/en-us/HT214119Release Notes
- support.apple.com/en-us/HT214120Release Notes
- support.apple.com/en-us/HT214122Release Notes
- support.apple.com/en-us/HT214124Release Notes
Third-party and government advisories
- seclists.org/fulldisclosure/2024/Jul/16Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2024/Jul/18Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2024/Jul/19Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2024/Jul/21Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2024/Jul/22Mailing List, Third Party Advisory
Other references
Other vulnerabilities in iOS and iPadOS
- 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 Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
- 7.0 High severity
- 7.5 High severity
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
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