Linux: Use After Free
CVE-2024-27049 is a high-severity use after free vulnerability in Linux, 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 attacker with a low-privileged account, without any action from a user. The record lists versions 84470b48af03a818039d587478b415cbcb264ff5, 6d9930096e1f13cf6d9aabfbf95d0e05fb04144f, a5a5f4413d91f395cb2d89829d376d7393ad48b9 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 0.28% 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 84470b48af03a818039d587478b415cbcb264ff5 or 6d9930096e1f13cf6d9aabfbf95d0e05fb04144f or a5a5f4413d91f395cb2d89829d376d7393ad48b9, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.7.11 or 6.8.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | c948b5da6bbec742b433138e3e3f9537a85af2e5 up to, but not including, 84470b48af03a818039d587478b415cbcb264ff5; c948b5da6bbec742b433138e3e3f9537a85af2e5 up to, but not including, 6d9930096e1f13cf6d9aabfbf95d0e05fb04144f; c948b5da6bbec742b433138e3e3f9537a85af2e5 up to, but not including, a5a5f4413d91f395cb2d89829d376d7393ad48b9; 6.7 | 84470b48af03a818039d587478b415cbcb264ff5, 6d9930096e1f13cf6d9aabfbf95d0e05fb04144f, a5a5f4413d91f395cb2d89829d376d7393ad48b9 |
| Linux | Linux Kernel | 6.7 up to, but not including, 6.7.11; 6.8 up to, but not including, 6.8.2 | 6.7.11, 6.8.2 |
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
- 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:L/AC:L/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: wifi: mt76: mt7925e: fix use-after-free in free_irq() From commit a304e1b82808 ("[PATCH] Debug shared irqs"), there is a test to make sure the shared irq handler should be able to handle the unexpected event after deregistration. For this case, let's apply MT76_REMOVED flag to indicate the device was removed and do not run into the resource access anymore.
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
Recent Use After Free vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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