macOS: Improper Initialization
CVE-2023-27934 is a high-severity improper initialization 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 attacker with a low-privileged account, without any action from a user. The record lists versions 13.3, 12.6 as the first without the flaw, so updating macOS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.79% chance of exploitation within 30 days, higher than 79% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update macOS to 13.3 or 12.6, whichever matches your release line, or a later version.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
Affected products and versions
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
- 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:L/PR:L/UI:N/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 memory initialization issue was addressed. This issue is fixed in macOS Ventura 13.3, macOS Monterey 12.6.4. A remote attacker 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: Improper Initialization
The product does not initialize or incorrectly initializes a resource.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, in Java, if the programmer does not explicitly initialize a variable, then the code could produce a compile-time error (if the variable is local) or automatically initialize the variable to the default value for the variable's type. In Perl, if explicit initialization is not performed, then a default value of undef is assigned, which is interpreted as 0, false, or an equivalent value depending on the context in which the variable is accessed.
- Identify all variables and data stores that receive information from external sources, and apply input validation to make sure that they are only initialized to expected values.
- Explicitly initialize all your variables and other data stores, either during declaration or just before the first usage.
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/HT213670Release Notes
Other references
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 Improper Initialization vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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