Linux: Use After Free
CVE-2024-40989 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 68df4fc449fcc24347209e500ce26d5816705a77, 48bb62859d47c5c4197a8c01128d0fa4f46ee58c, 152b4123f21e6aff31cea01158176ad96a999c76 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 0.3% 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 68df4fc449fcc24347209e500ce26d5816705a77 or 48bb62859d47c5c4197a8c01128d0fa4f46ee58c or 152b4123f21e6aff31cea01158176ad96a999c76 or 0d92e4a7ffd5c42b9fa864692f82476c0bf8bcc8, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.96 or 6.6.36 or 6.9.7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | e5a35635464bc5304674b84ea42615a3fd0bd949 up to, but not including, 68df4fc449fcc24347209e500ce26d5816705a77; e5a35635464bc5304674b84ea42615a3fd0bd949 up to, but not including, 48bb62859d47c5c4197a8c01128d0fa4f46ee58c; e5a35635464bc5304674b84ea42615a3fd0bd949 up to, but not including, 152b4123f21e6aff31cea01158176ad96a999c76; e5a35635464bc5304674b84ea42615a3fd0bd949 up to, but not including, 0d92e4a7ffd5c42b9fa864692f82476c0bf8bcc8; 5.13 | 68df4fc449fcc24347209e500ce26d5816705a77, 48bb62859d47c5c4197a8c01128d0fa4f46ee58c, 152b4123f21e6aff31cea01158176ad96a999c76, 0d92e4a7ffd5c42b9fa864692f82476c0bf8bcc8 |
| Linux | Linux Kernel | 5.13 up to, but not including, 6.1.96; 6.2 up to, but not including, 6.6.36; 6.7 up to, but not including, 6.9.7; 6.10 | 6.1.96, 6.6.36, 6.9.7 |
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.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Disassociate vcpus from redistributor region on teardown When tearing down a redistributor region, make sure we don't have any dangling pointer to that region stored in a vcpu.
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
Other references
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
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- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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