Apple Multiple Products Memory Corruption
CVE-2022-48618 is a high-severity time-of-check time-of-use (TOCTOU) race condition vulnerability in tvOS 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 attacker with a low-privileged account, without any action from a user. The record lists version 16.2 as the first without the flaw, so updating tvOS to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on January 31, 2024, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update tvOS to 16.2 or a later version.
- Update macOS to 13.1 or a later version.
- Update iOS and iPadOS to 16.2 or a later version.
- CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apple | tvOS | before 16.2 | 16.2 |
| Apple | macOS | before 13.1 | 13.1 |
| Apple | iOS and iPadOS | before 16.2 | 16.2 |
| Apple | watchOS | before 9.2; before 16.2 | 9.2, 16.2 |
| Apple | iphone_os | before 16.2 | 16.2 |
| Apple | ipados | before 16.2 | 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
- 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:L/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 | 7.0 | High | NVD |
| CVSS 3.1 | 7.0 | High | CISA (ADP) |
Official description
The issue was addressed with improved checks. This issue is fixed in macOS Ventura 13.1, watchOS 9.2, iOS 16.2 and iPadOS 16.2, tvOS 16.2. An attacker with arbitrary read and write capability may be able to bypass Pointer Authentication. Apple is aware of a report that this issue may have been exploited against versions of iOS released before iOS 15.7.1.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Time-of-check Time-of-use (TOCTOU) Race Condition
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
How developers prevent this class of flaw
- The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
- When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
- Limit the interleaving of operations on files from multiple processes.
More Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities (CWE-367)
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, 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/HT213532Release Notes
- support.apple.com/en-us/HT213535Release Notes
- support.apple.com/en-us/HT213536Release Notes
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-48618US Government Resource
Other vulnerabilities in tvOS
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
- 7.8 High severity
Recent Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities
- 7.0 High severity
- 7.0 High severity
- 8.1 High severity
- 7.0 High severity
- 7.5 High severity
- 7.1 High severity
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