Linux: Use After Free
CVE-2024-38561 is a high-severity use after free vulnerability in Linux, 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 versions 1f2ebd3758e1cef6a1f998a1f7ea73310dcb1699, 1ec7ccb4cd4b6f72c2998b07880fa7aaf8dfe1d4, 8f5c841a559ccb700c8d27a3ca645b7a5f59b4f5 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.23% 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 Linux to 1f2ebd3758e1cef6a1f998a1f7ea73310dcb1699 or 1ec7ccb4cd4b6f72c2998b07880fa7aaf8dfe1d4 or 8f5c841a559ccb700c8d27a3ca645b7a5f59b4f5 or b0b755cb5a5e0d7168c3ab1b3814b0d3cad9f017, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.93 or 6.6.33 or 6.8.12 or 6.9.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | adf505457032c11b79b5a7c277c62ff5d61b17c2 up to, but not including, 1f2ebd3758e1cef6a1f998a1f7ea73310dcb1699; adf505457032c11b79b5a7c277c62ff5d61b17c2 up to, but not including, 1ec7ccb4cd4b6f72c2998b07880fa7aaf8dfe1d4; adf505457032c11b79b5a7c277c62ff5d61b17c2 up to, but not including, 8f5c841a559ccb700c8d27a3ca645b7a5f59b4f5; adf505457032c11b79b5a7c277c62ff5d61b17c2 up to, but not including, b0b755cb5a5e0d7168c3ab1b3814b0d3cad9f017; adf505457032c11b79b5a7c277c62ff5d61b17c2 up to, but not including, f8aa1b98ce40184521ed95ec26cc115a255183b2; 5.18 | 1f2ebd3758e1cef6a1f998a1f7ea73310dcb1699, 1ec7ccb4cd4b6f72c2998b07880fa7aaf8dfe1d4, 8f5c841a559ccb700c8d27a3ca645b7a5f59b4f5, b0b755cb5a5e0d7168c3ab1b3814b0d3cad9f017, f8aa1b98ce40184521ed95ec26cc115a255183b2 |
| Linux | Linux Kernel | 5.18 up to, but not including, 6.1.93; 6.2 up to, but not including, 6.6.33; 6.7 up to, but not including, 6.8.12; 6.9 up to, but not including, 6.9.3 | 6.1.93, 6.6.33, 6.8.12, 6.9.3 |
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.
Official description
In the Linux kernel, the following vulnerability has been resolved: kunit: Fix kthread reference There is a race condition when a kthread finishes after the deadline and before the call to kthread_stop(), which may lead to use after free.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/1ec7ccb4cd4b6f72c2998b07880fa7aaf8dfe1d4
- git.kernel.org/stable/c/1f2ebd3758e1cef6a1f998a1f7ea73310dcb1699
- git.kernel.org/stable/c/8f5c841a559ccb700c8d27a3ca645b7a5f59b4f5
- git.kernel.org/stable/c/b0b755cb5a5e0d7168c3ab1b3814b0d3cad9f017
- git.kernel.org/stable/c/f8aa1b98ce40184521ed95ec26cc115a255183b2
Recent Use After Free vulnerabilities
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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