iOS and iPadOS: Improperly Controlled Sequential Memory Allocation
CVE-2024-27796 is a high-severity improperly controlled sequential memory allocation vulnerability in iOS and iPadOS from Apple, with a CVSS 3.1 base score of 7.8 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 versions 16.7.8, 17.5 as the first without the flaw, so updating iOS and iPadOS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.26% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update iOS and iPadOS to 16.7.8 or 17.5, whichever matches your release line, or a later version.
- Update macOS to 12.7.5 or 13.6.7 or 14.5, whichever matches your release line, or a later version.
- Update ipad_os to 17.5 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 | iOS and iPadOS | before 16.7.8; before 17.5 | 16.7.8, 17.5 |
| Apple | macOS | before 12.7.5; before 13.6.7; before 14.5 | 12.7.5, 13.6.7, 14.5 |
| Apple | ipad_os | before 17.5 | 17.5 |
| Apple | iphone_os | before 17.5 | 17.5 |
| Apple | iPadOS | before 16.7.8; 17.0 up to, but not including, 17.5 | 16.7.8, 17.5 |
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
- LowNo special conditions are needed; the attack works reliably.
- 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:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 8.1 | High | CISA (ADP) |
Official description
The issue was addressed with improved checks. This issue is fixed in iOS 16.7.8 and iPadOS 16.7.8, iOS 17.5 and iPadOS 17.5, macOS Monterey 12.7.5, macOS Sonoma 14.5, macOS Ventura 13.6.7. An attacker may be able to elevate privileges.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improperly Controlled Sequential Memory Allocation
The product manages a group of objects or resources and performs a separate memory allocation for each object, but it does not properly limit the total amount of memory that is consumed by all of the combined objects.
How developers prevent this class of flaw
- Ensure multiple allocations of the same kind of object are properly tracked - possibly across multiple sessions, requests, or messages. Define an appropriate strategy for handling requests that exceed the limit, and consider supporting a configuration option so that the administrator can extend the amount of memory to be used if necessary.
- Run the program using system-provided resource limits for memory. This might still cause the program to crash or exit, but the impact to the rest of the system will be minimized.
More Improperly Controlled Sequential Memory Allocation vulnerabilities (CWE-1325)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
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
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